CVE-2021-3156
Sudo Heap-Based Buffer Overflow Vulnerability
IN CISA KEV
Sudo before 1.9.5p2 contains an off-by-one error that can result in a heap-based buffer overflow, which allows privilege escalation to root via "sudoedit -s" and a command-line argument that ends with a single backslash character.
- Vendor
- Sudo
- Product
- Sudo
- CVSS 3.1
- 7.8 (high), scored by NVD (primary)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CVSS 3.1
- 7.8 (high), scored by 134c704f-9b21-4f2e-91b3-4a467353bcc0CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CWE
- CWE-193
- Published
- 2021-01-26
- NVD modified
- 2026-06-17
- NVD status
- Analyzed
CISA KEV
- Date added
- 2022-04-06
- Due date
- 2022-04-27
- Ransomware use
- Unknown
- Required action
- Apply updates per vendor instructions.
EPSS
100% chance of exploitation in the next 30 days (percentile 99th)
FIRST EPSS, updated 17 Oct 2026. About EPSS
CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.
References
- seclists.org (Mailing List, Third Party Advisory)
- www.openwall.com (Mailing List, Third Party Advisory)
- www.openwall.com (Mailing List, Third Party Advisory)
- www.openwall.com (Mailing List, Patch, Third Party Advisory)
- www.openwall.com (Mailing List)
- kc.mcafee.com (Broken Link, Third Party Advisory)
- lists.debian.org (Mailing List, Third Party Advisory)
- lists.fedoraproject.org (Mailing List, Release Notes)
- lists.fedoraproject.org (Mailing List, Release Notes)
- security.gentoo.org (Third Party Advisory)
- security.netapp.com (Third Party Advisory)
- security.netapp.com (Third Party Advisory)
Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.