Out-of-bounds Read in Squirrel-Lang Squirrel
CVE-2021-41556
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.028 (85.7th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 86th percentile — 85.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.027 · newest: 0.028 · change: +0.001
Affected products
- Squirrel-Lang Squirrel
- Fedoraproject Fedora — versions 35, 36
Weakness classification (CWE)
References
- github.com/albertodemichelis/squirrel/commit/23a0620658714b996d20da3d4dd1a0dcf9… (Patch, Third Party Advisory)
- www.squirrel-lang.org/ (Third Party Advisory)
- blog.sonarsource.com/squirrel-vm-sandbox-escape/ (Exploit, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0
Frequently asked questions
- What is CVE-2021-41556?
- CVE-2021-41556 is a critical-severity vulnerability in Squirrel-Lang Squirrel, classified under Out-of-bounds Read. CVSS score: 10.0/10. Published 2022-07-28.
- How severe is CVE-2021-41556?
- Critical severity. CVSS v3 base score is 10.0 out of 10.