VIR Vulnerability Intelligence Relay

CVE-2021-41556

critical
Published 2022-07-28 · Modified 2026-05-29
💬 Discuss on Community ✚ Propose mitigation
CVSS v3
10.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS v4 NEW
—
not yet in upstream
VIR risk
10.0

Description

sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that can lead to Code Execution. If a victim executes an attacker-controlled squirrel script, it is possible for the attacker to break out of the squirrel script sandbox even if all dangerous functionality such as File System functions has been disabled. An attacker might abuse this bug to target (for example) Cloud services that allow customization via SquirrelScripts, or distribute malware through video games that embed a Squirrel Engine.

Predictions

Exploit likelihood
98%
Patch ETA
—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact
debian Debian Affected 4 releases
VersionStatusFixed in
trixie Affected —
sid Affected —
forky Affected —
bullseye Affected —
fedora Fedora Affected 2 releases
VersionStatusFixed in
36 Affected —
35 Affected —

Application impact
VendorProductVersionsFixed
squirrel-langsquirrel{"endIncluding":"2.2.5"}
squirrel-langsquirrel{"startIncluding":"3.0","endIncluding":"3.1"}

References

CWEs

CWE-125

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.