CVE-2021-3156
Published: April 6, 2022
Official Description
Sudo contains an off-by-one error that can result in a heap-based buffer overflow, which allows for privilege escalation.
CISA KEV Advisory
Sudo Heap-Based Buffer Overflow Vulnerability
Sudo contains an off-by-one error that can result in a heap-based buffer overflow, which allows for privilege escalation.
Apply updates per vendor instructions.
Risk Analysis
This vulnerability in Sudo, known as Baron Samedit, allows an attacker to gain elevated privileges on a system. The high EPSS score of 0.92483 indicates a very high likelihood of exploitation, making this a critical issue for systems using Sudo. It is confirmed to be actively exploited in the wild, as indicated by its presence in CISA's KEV catalog.
Active exploitation of this vulnerability has been observed in the wild, and it is listed in CISA's Known Exploited Vulnerabilities catalog. This indicates a significant and immediate threat.
System administrators should update Sudo to a patched version immediately to prevent privilege escalation. Regularly review and update all system components to mitigate known vulnerabilities.
Technical Analysis
CVE-2021-3156 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2021-3156 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-3156 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1