CVE-2021-41556

CRITICAL
Published Jul 28, 20223y ago · Modified Jun 17, 20262w ago
10.0 CVSS 3.1
Critical
Find Similar
Published Jul 28, 2022 3y ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
10.0
Exploitability
3.9
Impact
6.0
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Changed
Confidentiality High
Integrity High
Availability High

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-125 Out-of-bounds Read Memory Safety

Affected Products 4

VendorProductVersionRange
squirrel-langsquirrel* ≤2.2.5
squirrel-langsquirrel*≥3.0  –  ≤3.1
fedoraprojectfedora35any
fedoraprojectfedora36any

References 6

  • squirrel-lang.org http://www.squirrel-lang.org/#download
    Third Party Advisory
  • blog.sonarsource.com https://blog.sonarsource.com/squirrel-vm-sandbox-escape/
    ExploitThird Party Advisory
  • github.com https://github.com/albertodemichelis/squirrel/commit/23a0620658714b996d20da3d4dd1a0dcf9b0bd98
    PatchThird Party Advisory
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BV7SJJ44AGAX4ILIVPREIXPJ2GOG3FKV/
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M3FQILX7UUEERSDPMZP3MKGTMY2E7ESU/
  • sonarsource.com https://www.sonarsource.com/blog/squirrel-vm-sandbox-escape/

Remediation

  • github.com https://github.com/albertodemichelis/squirrel/commit/23a0620658714b996d20da3d4dd1a0dcf9b0bd98
    PatchThird Party Advisory