CVE intelligence and bounded remediation

CVE-2021-3156 — Sudo Heap-Based Buffer Overflow Vulnerability

High CVSS 7.8 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.

Severity
High
CVSS
7.8 (3.1)
Published
2021-01-26
CISA KEV
Known exploited
Ecosystem
software/application
Weaknesses
CWE-193

Affected products

  • sudo_project / sudo
  • sudo_project / sudo / 1.9.5
  • fedoraproject / fedora / 32
  • fedoraproject / fedora / 33
  • debian / debian_linux / 9.0
  • debian / debian_linux / 10.0

Showing 6 representative product identities from 32 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
  • Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
  • Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

  • Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
  • Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
  • Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.