CVE-2022-39394: bytecodealliance wasmtime Out-of-bounds Write

Vulnerability summary

CVE-2022-39394 is a critical (CVSS 9.8) Out-of-bounds Write vulnerability in bytecodealliance wasmtime. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 27.7% of scored vulnerabilities.

Timeline

1. 10-11-2022
   PublishedVulnerability first disclosed.
2. 23-04-2025
   Last modifiedVulnerability information updated.

Description

Wasmtime is a standalone runtime for WebAssembly. Prior to version 2.0.2, there is a bug in Wasmtime's C API implementation where the definition of the `wasmtime_trap_code` does not match its declared signature in the `wasmtime/trap.h` header file. This discrepancy causes the function implementation to perform a 4-byte write into a 1-byte buffer provided by the caller. This can lead to three zero bytes being written beyond the 1-byte location provided by the caller. This bug has been patched and users should upgrade to Wasmtime 2.0.2. This bug can be worked around by providing a 4-byte buffer casted to a 1-byte buffer when calling `wasmtime_trap_code`. Users of the `wasmtime` crate are not affected by this issue, only users of the C API function `wasmtime_trap_code` are affected.

• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.