Vulnerability Description
The WebAssembly Micro Runtime's (WAMR) iwasm package is the executable binary built with WAMR VMcore which supports WebAssembly System Interface (WASI) and command line interface. Anyone running WAMR up to and including version 2.2.0 or WAMR built with libc-uvwasi on Windows is affected by a symlink following vulnerability. On WAMR running in Windows, creating a symlink pointing outside of the preopened directory and subsequently opening it with create flag will create a file on host outside of the sandbox. If the symlink points to an existing host file, it's also possible to open it and read its content. Version 2.3.0 fixes the issue.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Bytecodealliance | Webassembly Micro Runtime | < 2.2.0 |
Related Weaknesses (CWE)
References
- https://github.com/bytecodealliance/wasm-micro-runtime/commit/28702edaf739cdeee5Patch
- https://github.com/bytecodealliance/wasm-micro-runtime/security/advisories/GHSA-ExploitThird Party Advisory
FAQ
What is CVE-2025-43853?
CVE-2025-43853 is a vulnerability with a CVSS score of 5.5 (MEDIUM). The WebAssembly Micro Runtime's (WAMR) iwasm package is the executable binary built with WAMR VMcore which supports WebAssembly System Interface (WASI) and command line interface. Anyone running WAMR ...
How severe is CVE-2025-43853?
CVE-2025-43853 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-43853?
Check the references section above for vendor advisories and patch information. Affected products include: Bytecodealliance Webassembly Micro Runtime.