GNU · Bourne-Again Shell (Bash)
CVE-2014-6271
GNU Bourne-Again Shell (Bash) Arbitrary Code Execution Vulnerability
What it is
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.
What to do
Apply updates per vendor instructions.
Deadline for US federal agencies: July 28, 2022
- Added to the CISA list
- January 28, 2022
- Published
- September 24, 2014
- Severity
- Critical 9.8 CVSS 3.1
- Chance of attacks in the next 30 days (EPSS)
- >99.9% in the top 0.1% of all known vulnerabilities
- Weakness
- CWE-78
- More details
- NVD · CVE.org · CISA
All references (20)
- http://lists.opensuse.org/opensuse-security-announce/2014-09/msg00034.html
- http://marc.info/?l=bugtraq&m=141577137423233&w=2
- http://marc.info/?l=bugtraq&m=142719845423222&w=2
- http://marc.info/?l=bugtraq&m=141216668515282&w=2
- http://rhn.redhat.com/errata/RHSA-2014-1295.html
- http://lists.opensuse.org/opensuse-security-announce/2014-09/msg00037.html
- http://marc.info/?l=bugtraq&m=141383138121313&w=2
- http://marc.info/?l=bugtraq&m=142721162228379&w=2
- http://marc.info/?l=bugtraq&m=142358026505815&w=2
- http://marc.info/?l=bugtraq&m=142719845423222&w=2
- https://www.exploit-db.com/exploits/37816/
- http://packetstormsecurity.com/files/128517/VMware-Security-Advisory-2014-0010.html
- http://www-01.ibm.com/support/docview.wss?uid=ssg1S1004897
- http://www-01.ibm.com/support/docview.wss?uid=swg21685749
- https://www.exploit-db.com/exploits/39918/
- https://securityblog.redhat.com/2014/09/24/bash-specially-crafted-environment-variables-code-injection-attack/
- https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk1…
- http://www.securityfocus.com/archive/1/533593/100/0/threaded
- http://www-01.ibm.com/support/docview.wss?uid=swg21686084
- http://www-01.ibm.com/support/docview.wss?uid=swg21686479
More exploited flaws from GNU
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Jan 28, 2022 | Arbitrary Code Execution | Bourne-Again Shell (Bash) | Critical 9.8 | 99.9% |
| Jan 26, 2026 | Argument Injection | InetUtils | Critical 9.8 | 99% |
| Oct 2, 2025 | Bash OS Command Injection | GNU Bash | High 8.8 | 99.7% |
| Nov 21, 2023 | C Library Buffer Overflow | GNU C Library | High 7.8 | 64% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.