[ CVE-2014-6271 · Published 24 Sep 2014 ]

GNU Bourne-Again Shell (Bash) Arbitrary Code Execution Vulnerability

Exploited · CISA KEV CVSS 9.8 EPSS 100%Fix available

[ Why it matters ]Priority signals

  • Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2022-01-28
  • EPSS: 100% chance of exploitation in the next 30 days (higher than 100% of CVEs)
  • Critical severity: CVSS 9.8

[ Description ]Official description

GNU Bash through 4.3 processes trailing strings after function definitions in the values of environment variables, which allows remote attackers to execute arbitrary code via a crafted environment, as demonstrated by vectors involving the ForceCommand feature in OpenSSH sshd, the mod_cgi and mod_cgid modules in the Apache HTTP Server, scripts executed by unspecified DHCP clients, and other situations in which setting the environment occurs across a privilege boundary from Bash execution, aka "ShellShock." NOTE: the original fix for this issue was incorrect; CVE-2014-7169 has been assigned to cover the vulnerability that is still present after the incorrect fix.

CISA: GNU Bash through 4.3 processes trailing strings after function definitions in the values of environment variables, which allows remote attackers to execute code.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 28 Jul 2022): Apply updates per vendor instructions.

[ References ]References