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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2014-6271

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

KEVCRITICAL 9.8EPSS 100.0%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 28 July 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

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.

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
100.00% probability · 100th percentile
CISA KEV
Listed 28 January 2022 · due 28 July 2022
Weakness
CWE-78
Affected
gnu/bash · arista/eos · oracle/linux · qnap/qts · mageia/mageia · redhat/gluster storage server for on-premise · redhat/virtualization · redhat/enterprise linux · redhat/enterprise linux desktop · redhat/enterprise linux eus · redhat/enterprise linux for ibm z systems · redhat/enterprise linux for power big endian · redhat/enterprise linux for power big endian eus · redhat/enterprise linux for scientific computing · redhat/enterprise linux server · redhat/enterprise linux server aus · redhat/enterprise linux server from rhui · redhat/enterprise linux server tus · redhat/enterprise linux workstation · suse/studio onsite · +40 more
Source
security@debian.org

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2014-6271

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.