CVE-2021-3156
Publication date 26 January 2021
Last updated 25 August 2025
Ubuntu priority
Description
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| sudo | ||
| 20.04 LTS focal |
Fixed 1.8.31-1ubuntu1.2
|
|
| 18.04 LTS bionic |
Fixed 1.8.21p2-3ubuntu1.4
|
|
| 16.04 LTS xenial |
Fixed 1.8.16-0ubuntu1.10
|
|
| 14.04 LTS trusty |
Fixed 1.8.9p5-1ubuntu1.5+esm6
|
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Get Ubuntu Pro 30-day free trialSeverity score breakdown
| Parameter | Value |
|---|---|
| Base score |
7.8 · High
|
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
References
Related Ubuntu Security Notices (USN)
- USN-4705-1
- Sudo vulnerabilities
- 26 January 2021
- USN-4705-2
- Sudo vulnerability
- 27 January 2021