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CVE-2021-3156

Published: Jan 26, 2021Updated: Nov 10, 2025 Sources: CVE List NVD BDU csafCWE-193
NVD MITRE
7.8CVSSHIGH
EPSS Score
99.3%
Top 0.1%
CISA KEV
Active Exploitation
Since Apr 6, 2022
Exploits
8 Known
Remediation
Patch Available
Am I actually vulnerable?1 Nuclei template available — see how to check your systems. How to verify

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.

CVSS Vector Breakdown

AV:LAC:LPR:LUI:NS:UC:HI:HA:H
Exploitability
AV:LAttack Vector
Local
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-193

Affected Products

sudosudo project
Mixed
Operating Systems / unix-bsd
fedorafedoraproject
On-premOS
Operating Systems / linux-distro
debian linuxdebian
On-premOS
Operating Systems / linux-distro
active iq unified managernetappHardware Firmware
cloud backupnetappHardware Firmware
sudo projectoss-projectUSOperating Systemsaka sudo
fedoraprojectoss-projectUSOperating Systemsaka fedora project
debianoss-projectGBOperating Systemsaka debian gnu/linux
netappcommercialUSHardware Firmware
and 36 more affected products View all →

Exploitability

CISA Known Exploited Vulnerability
Added to KEV:Apr 6, 2022
Remediation due:Apr 27, 2022

Required action: Apply updates per vendor instructions.

8 exploit sources identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available

References

http://packetstormsecurity.com/files/161160/Sudo-Heap-Based-Buffer-Overflow.html
packetstormsecurity.com
http://packetstormsecurity.com/files/161230/Sudo-Buffer-Overflow-Privilege-Escalation.html
packetstormsecurity.com
http://packetstormsecurity.com/files/161270/Sudo-1.9.5p1-Buffer-Overflow-Privilege-Escalation.html
packetstormsecurity.com
and 69 more references View all →

Timeline

Published
Jan 26, 2021
Added to CISA KEV
Apr 6, 2022
Last Updated
Nov 10, 2025

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