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wasmtime_trap_code C API function has out of bounds write vulnerability

Low severity GitHub Reviewed Published Nov 10, 2022 in bytecodealliance/wasmtime • Updated May 2, 2025

Package

cargo wasmtime (Rust)

Affected versions

>= 2.0.0, < 2.0.2
< 1.0.2

Patched versions

2.0.2
1.0.2

Description

Impact

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.

Patches

This bug has been patched and users should upgrade to Wasmtime 2.0.2.

Workarounds

This 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.

References

For more information

If you have any questions or comments about this advisory:

References

@alexcrichton alexcrichton published to bytecodealliance/wasmtime Nov 10, 2022
Published by the National Vulnerability Database Nov 10, 2022
Published to the GitHub Advisory Database Feb 1, 2024
Reviewed Feb 1, 2024
Last updated May 2, 2025

Severity

Low

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
High
Privileges required
High
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(13th percentile)

Weaknesses

Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer. Learn more on MITRE.

CVE ID

CVE-2022-39394

GHSA ID

GHSA-h84q-m8rr-3v9q

Source code

Credits

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