CWE-67
AllowedImproper Handling of Windows Device Names
Abstraction: Variant · Status: Incomplete
The product constructs pathnames from user input, but it does not handle or incorrectly handles a pathname containing a Windows device name such as AUX or CON. This typically leads to denial of service or an information exposure when the application attempts to process the pathname as a regular file.
12 vulnerabilities reference this CWE, most recent first.
GHSA-C2F5-JXJV-2HH8
Vulnerability from github – Published: 2024-11-05 22:18 – Updated: 2025-05-02 12:53Impact
Wasmtime's filesystem sandbox implementation on Windows blocks access to special device filenames such as "COM1", "COM2", "LPT0", "LPT1", and so on, however it did not block access to the special device filenames which use superscript digits, such as "COM¹", "COM²", "LPT⁰", "LPT¹", and so on. Untrusted Wasm programs that are given access to any filesystem directory could bypass the sandbox and access devices through those special device filenames with superscript digits, and through them gain access peripheral devices connected to the computer, or network resources mapped to those devices. This can include modems, printers, network printers, and any other device connected to a serial or parallel port, including emulated USB serial ports.
Patches
Patch releases for Wasmtime have been issued as 24.0.2, 25.0.3, and 26.0.1. Users of Wasmtime 23.0.x and prior are recommended to upgrade to one of these patched versions.
Workarounds
There are no known workarounds for this issue. Affected Windows users are recommended to upgrade.
References
- Microsoft's documentation of the special device filenames
- ISO-8859-1
- The original PR reporting the issue
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "wasmtime"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "24.0.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "crates.io",
"name": "wasmtime"
},
"ranges": [
{
"events": [
{
"introduced": "25.0.0"
},
{
"fixed": "25.0.3"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "crates.io",
"name": "wasmtime"
},
"ranges": [
{
"events": [
{
"introduced": "26.0.0"
},
{
"fixed": "26.0.1"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"26.0.0"
]
}
],
"aliases": [
"CVE-2024-51745"
],
"database_specific": {
"cwe_ids": [
"CWE-184",
"CWE-67"
],
"github_reviewed": true,
"github_reviewed_at": "2024-11-05T22:18:49Z",
"nvd_published_at": "2024-11-05T22:15:21Z",
"severity": "LOW"
},
"details": "### Impact\n\nWasmtime\u0027s filesystem sandbox implementation on Windows blocks access to special device filenames such as \"COM1\", \"COM2\", \"LPT0\", \"LPT1\", and so on, however it did not block access to the special device filenames which use superscript digits, such as \"COM\u00b9\", \"COM\u00b2\", \"LPT\u2070\", \"LPT\u00b9\", and so on. Untrusted Wasm programs that are given access to any filesystem directory could bypass the sandbox and access devices through those special device filenames with superscript digits, and through them gain access peripheral devices connected to the computer, or network resources mapped to those devices. This can include modems, printers, network printers, and any other device connected to a serial or parallel port, including emulated USB serial ports.\n\n### Patches\n\nPatch releases for Wasmtime have been issued as 24.0.2, 25.0.3, and 26.0.1. Users of Wasmtime 23.0.x and prior are recommended to upgrade to one of these patched versions.\n\n### Workarounds\n\nThere are no known workarounds for this issue. Affected Windows users are recommended to upgrade.\n\n### References\n\n - [Microsoft\u0027s documentation](https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file#naming-conventions) of the special device filenames\n - [ISO-8859-1](https://en.wikipedia.org/wiki/ISO/IEC_8859-1)\n - [The original PR reporting the issue](https://github.com/bytecodealliance/cap-std/pull/371)",
"id": "GHSA-c2f5-jxjv-2hh8",
"modified": "2025-05-02T12:53:57Z",
"published": "2024-11-05T22:18:49Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-c2f5-jxjv-2hh8"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-51745"
},
{
"type": "WEB",
"url": "https://github.com/bytecodealliance/cap-std/pull/371"
},
{
"type": "WEB",
"url": "https://en.wikipedia.org/wiki/ISO/IEC_8859-1"
},
{
"type": "PACKAGE",
"url": "https://github.com/bytecodealliance/wasmtime"
},
{
"type": "WEB",
"url": "https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file#naming-conventions"
},
{
"type": "WEB",
"url": "https://rustsec.org/advisories/RUSTSEC-2024-0438.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Wasmtime doesn\u0027t fully sandbox all the Windows device filenames"
}
GHSA-HGF8-39GV-G3F2
Vulnerability from github – Published: 2025-12-02 00:27 – Updated: 2025-12-02 00:27Werkzeug's safe_join function allows path segments with Windows device names. On Windows, there are special device names such as CON, AUX, etc that are implicitly present and readable in every directory. send_from_directory uses safe_join to safely serve files at user-specified paths under a directory. If the application is running on Windows, and the requested path ends with a special device name, the file will be opened successfully, but reading will hang indefinitely.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "werkzeug"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.1.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-66221"
],
"database_specific": {
"cwe_ids": [
"CWE-67"
],
"github_reviewed": true,
"github_reviewed_at": "2025-12-02T00:27:38Z",
"nvd_published_at": "2025-11-29T03:16:00Z",
"severity": "MODERATE"
},
"details": "Werkzeug\u0027s `safe_join` function allows path segments with Windows device names. On Windows, there are special device names such as `CON`, `AUX`, etc that are implicitly present and readable in every directory. `send_from_directory` uses `safe_join` to safely serve files at user-specified paths under a directory. If the application is running on Windows, and the requested path ends with a special device name, the file will be opened successfully, but reading will hang indefinitely.",
"id": "GHSA-hgf8-39gv-g3f2",
"modified": "2025-12-02T00:27:38Z",
"published": "2025-12-02T00:27:38Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/pallets/werkzeug/security/advisories/GHSA-hgf8-39gv-g3f2"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-66221"
},
{
"type": "WEB",
"url": "https://github.com/pallets/werkzeug/commit/4b833376a45c323a189cd11d2362bcffdb1c0c13"
},
{
"type": "PACKAGE",
"url": "https://github.com/pallets/werkzeug"
},
{
"type": "WEB",
"url": "https://github.com/pallets/werkzeug/releases/tag/3.1.4"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Werkzeug safe_join() allows Windows special device names"
}
Mitigation
Be familiar with the device names in the operating system where your system is deployed. Check input for these device names.
No CAPEC attack patterns related to this CWE.