GNU Bourne-Again Shell (Bash) Arbitrary Code Execution Vulnerability
GNU · Bourne-Again Shell (Bash)
GNU Bourne-Again Shell (Bash) through 4.3 bash43-025 mishandles trailing strings after certain malformed function definitions in environment variable values, which is an improper neutralization of special elements in OS commands. An attacker with network access and no authentication or user interaction can, by crafting an environment passed across a privilege boundary (for example via OpenSSH sshd ForceCommand, Apache mod_cgi or mod_cgid, or DHCP client scripts), write to files or potentially achieve other unspecified impact.
GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed function definitions in the values of environment variables, which allows remote attackers to write to files or possibly have unknown other impact 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.
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 3/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 5 days after disclosure. Public exploit code (Exploit-DB) was available the same day.
- First seen exploitedVulnCheck KEV evidence+5 days
- Added to CISA KEVEU database agrees+7 yrs
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
Patch historyEarlier and later CVEs in the same code, in date order. It shows when a fix was bypassed or incomplete and which version finally fixed it.
See the family treeA fix was bypassed or incomplete 3 times over 6 days.
Same bug familyLinked by evidence that a fix failed or the same code was patched again. Oldest first.
incomplete fixHigh
Why these are linked: Link confidenceHow strong the evidence is that two CVEs are related. High: stated in the CVE text or linked in an advisory, or the same code was patched one release apart. Medium: the same code, or a version step plus a similar description. Low: similar description only.
- Stated in the CVE text
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.
- Stated in the CVE text
NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-6271.
- Similar weakness in the same product (machine-matched)same product + CWE + description similarity
This CVECVE-2014-7169GNU Bourne-Again Shell (Bash) Arbitrary Code Execution25 Sep 2014KEV- Stated in the CVE text
incomplete fixHigh
Why these are linked: Link confidenceHow strong the evidence is that two CVEs are related. High: stated in the CVE text or linked in an advisory, or the same code was patched one release apart. Medium: the same code, or a version step plus a similar description. Low: similar description only.
- Stated in the CVE text
NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-6271 and CVE-2014-7169.
- Stated in the CVE text
incomplete fixHigh
Why these are linked: Link confidenceHow strong the evidence is that two CVEs are related. High: stated in the CVE text or linked in an advisory, or the same code was patched one release apart. Medium: the same code, or a version step plus a similar description. Low: similar description only.
- Stated in the CVE text
NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-6271, CVE-2014-7169, and CVE-2014-6277.
- Stated in the CVE text
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
3 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order 3Initial AccessTA0001
CVE-2014-7169 allows environment variables set from service/HTTP requests on a serve (e.g. HTTP_COOKIE) in Bash shell that allows for spawning a child shell with the authority/privilege level of the parent shell to perform RCE of code provided by the adversary in the request.
ExecutionTA0002
Lower-confidence links (1)
These come from early or generic mappings, text matching, or contradict this CVE’s details (for example a public-facing technique on a bug that needs a user to open a file). Shown for completeness.
- Exploitation for Client ExecutionT1203 server-side bug exploitable without user interaction; client-execution technique does not fit
Detection
0 rules for this CVE · 188 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2014-7169 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
External Remote ServicesT113320 general rules
- External Remote SMB Logon from Public IPhightest
- OpenCanary - SSH Login Attempthightest
- OpenCanary - SSH New Connection Attempthightest
- OpenCanary - Telnet Login Attempthightest
- Running Chrome VPN Extensions via the Registry 2 VPN Extensionhightest
- Unusual Child Process of dns.exehightest
- Unusual File Deletion by Dns.exehightest
- Unusual File Modification by dns.exehightest
Exploit Public-Facing ApplicationT1190149 general rules
- Arcadyan Router Exploitationscriticaltest
- Citrix ADS Exploitation CVE-2020-8193 CVE-2020-8195criticaltest
- Citrix Netscaler Attack CVE-2019-19781criticaltest
- Confluence Exploitation CVE-2019-3398criticaltest
- CVE-2010-5278 Exploitation Attemptcriticaltest
- CVE-2020-0688 Exchange Exploitation via Web Logcriticaltest
- CVE-2020-10148 SolarWinds Orion API Auth Bypasscriticaltest
- CVE-2020-5902 F5 BIG-IP Exploitation Attemptcriticaltest
Unix ShellT1059.00419 general rules
- Linux Reverse Shell Indicatorcriticaltest
- AWS EC2 Startup Shell Script Changehightest
- Equation Group Indicatorshightest
- JexBoss Command Sequencehightest
- Shell Invocation via Env Command - Linuxhightest
- Suspicious Activity in Shell Commandshightest
- Suspicious Reverse Shell Command Linehightest
- Axios NPM Compromise Indicators - Linuxhighexperimental
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Not named in any threat report yetAlso mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- Actively_Exploited_Kev | Oct 24, 202623 Oct 2026
- Actively_Exploited_Kev | Oct 23, 202622 Oct 2026
- Actively_Exploited_Kev | Oct 22, 202621 Oct 2026
- 44 more on OTX