CVE-2014-6271
CVE-2014-6271 is a security flaw in GNU Bourne-Again Shell (Bash). Attackers can run their own code on GNU Bourne-Again Shell (Bash). The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 28 Jan 2022.[1]
GNU Bourne-Again Shell (Bash) is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. GNU has published a fix or advice.
Description
CISA calls it an arbitrary code execution in GNU Bourne-Again Shell (Bash). In its words: “GNU Bash through 4.3 processes trailing strings after function definitions in the values of environment variables, which allows remote attackers to execute code.”[1]
The CVE record adds: “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.”[2]
The underlying weakness is OS command injection (CWE-78), in MITRE’s list of common software weaknesses.
It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; GNU’s advisory has them[3]. CISA names the product as GNU Bourne-Again Shell (Bash).
Most families won’t have GNU Bourne-Again Shell (Bash); it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 28 Jan 2022, 2,683 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 28 Jul 2022 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at over 99%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
GNU has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Check whether you use it.GNU Bourne-Again Shell (Bash) is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 28 Jul 2022 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at over 99%.[4] |
See also
Other GNU Bourne-Again Shell (Bash) flaws
- CVE-2014-7169: arbitrary code execution ·
Other GNU flaws
- CVE-2026-24061, GNU InetUtils: argument injection ·
- CVE-2014-6278, GNU Bash: bash OS command injection ·
- CVE-2023-4911, GNU C Library: c library buffer overflow ·
Other OS command injection flaws
- CVE-2026-110447, Collabora Online – Built-in CODE Server: online – built-in CODE server OS command injection ·
- CVE-2026-106931, EG Secure Solutions SiteGuard Server Edition: OS command injection ·
- CVE-2026-83549, SonicWall SMA1000 Appliances: OS command injection ·
- CVE-2026-49869, Kestra OSS: OSS OS command injection ·
- CVE-2026-73570, Synacor Zimbra Collaboration Suite (ZCS): OS command injection ·
Added the same day
- CVE-2022-22587, Apple iOS and macOS: memory corruption ·
- CVE-2021-20038, SonicWall SMA 100 Appliances: stack-based buffer overflow ·
- CVE-2020-5722, Grandstream UCM6200: networks UCM6200 series SQL injection ·
- CVE-2020-0787, Microsoft Windows: background intelligent transfer service (BITS) improper privilege management ·
- CVE-2017-5689, Intel Active Management Technology (AMT), Small Business Technology (SBT), and Standard Manageability: privilege escalation ·
Every GNU flaw on CISA’s list · Everything added in January 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “GNU Bourne-Again Shell (Bash) Arbitrary Code Execution Vulnerability”. Known Exploited Vulnerabilities Catalog, added 28 Jan 2022.
- ^ National Institute of Standards and Technology. “CVE-2014-6271 Detail”. National Vulnerability Database, published 24 Sep 2014.
- ^ GNU. Advisories and fixes: bugzilla.redhat.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 1.000, percentile 100.0, 31 Oct 2026.
- CVE Program. “CVE-2014-6271”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.