VulnerabilityAnalyzed

CVE-2025-43853

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.

HIGH 7.0EPSS 0.27%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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 4.0: 7.0 HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.27% probability · 20th percentile
CISA KEV: Not listed
Weakness: CWE-61
Affected: bytecodealliance/webassembly micro runtime
Source: security-advisories@github.com

References

https://github.com/bytecodealliance/wasm-micro-runtime/commit/28702edaf739cdeee54e81efe5868bf00724c33cPatch
https://github.com/bytecodealliance/wasm-micro-runtime/security/advisories/GHSA-8fc8-4g25-c8m7Exploit, Third Party Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.