Threats / GNU / CVE-2014-6271
CVE-2014-6271
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-16
GNU Bourne-Again Shell (Bash) vulnerability
GNU Bash through 4.3 allows remote code execution through environment variable function definitions with trailing strings, enabling arbitrary command execution on affected systems.
Verdict
Today item — known-exploited.
This vulnerability permits unauthenticated remote attackers to execute arbitrary code by injecting malicious function definitions into environment variables. The high EPSS score and active exploitation in the wild indicate severe risk requiring immediate patching of all affected Bash installations.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
40 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-01-28).
Probability (EPSS)
EPSS 0.99999 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: GNU, Bourne-Again Shell (Bash). Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-78 OS Command Injection — weakness family: Injection.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No threat-actor attribution is established from the public feed for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious environment variable containing a function definition followed by shell commands.
Business
An attacker gains code execution on web servers, mail servers, and other systems processing untrusted environment variables.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I deliver the payload through HTTP headers, CGI parameters, or DHCP options that become environment variables.
Business
Compromised systems become entry points for lateral movement, data exfiltration, and infrastructure takeover.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute commands with the privileges of the process running Bash, typically web server or system service accounts.
Business
Attackers establish persistent access, deploy malware, or pivot to critical internal systems and databases.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05
Coverage & confidence
— what we know, and what we don’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by debianCNA
Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.