CVE-2014-6271
Shellshock
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.
- CVSS
- 9.8Criticalscored by CISA
- Exploited in the wild
- Yes, in CISA KEV since 28 Jan 2022CISA deadline for US federal agencies: 28 Jul 2022public exploit code
- EPSS
- > 99.9%chance of exploitation in the next 30 daystop 0.1% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 24 Sept 2014analysed here 12 Nov 2026
Do first. Apply updates per vendor instructions. (CISA's required action for this KEV entry)
Summary
Triage
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
Products named in our analysis
- gnu:bash
- arista:eos
- oracle:linux
- qnap:qts
- mageia:mageia
- redhat:gluster_storage_server_for_on-premise
- redhat:virtualization
- redhat:enterprise_linux
- redhat:enterprise_linux_desktop
- redhat:enterprise_linux_eus
- redhat:enterprise_linux_for_ibm_z_systems
- redhat:enterprise_linux_for_power_big_endian
- redhat:enterprise_linux_for_power_big_endian_eus
- redhat:enterprise_linux_for_scientific_computing
- redhat:enterprise_linux_server
- redhat:enterprise_linux_server_aus
- redhat:enterprise_linux_server_from_rhui
- redhat:enterprise_linux_server_tus
- redhat:enterprise_linux_workstation
- suse:studio_onsite
- opensuse:opensuse
- suse:linux_enterprise_desktop
- suse:linux_enterprise_server
- suse:linux_enterprise_software_development_kit
- debian:debian_linux
- ibm:infosphere_guardium_database_activity_monitoring
- ibm:pureapplication_system
- ibm:qradar_risk_manager
- ibm:qradar_security_information_and_event_manager
- ibm:qradar_vulnerability_manager
Fix and mitigation
WAF and other mitigations
Can a WAF block it? Partly. Azure WAF and Google Cloud Armor publish WAF rules written for this CVE. Such rules block the known exploit requests and buy time, but attackers can change the request to get past them, so they do not replace the patch.
Also consider: patch · enable the vendor rule in block mode · shlex/execve-style APIs
Based on WAF vendor rules published for this CVE. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 28 Jan 2022.
- CISA due date
- 28 Jul 2022, the remediation deadline for US federal agencies
- CISA required action
- Apply updates per vendor instructions.
- Public exploit code
- Yes: 21 on Exploit-DB · 10 Metasploit modules · 96 GitHub proofs of concept · 1 Nuclei template
- CISA SSVC
- exploitation active, automatable yes, technical impact totalAssessed by CISA 7 Feb 2025 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
Exploit-DB
- Qmail SMTP - Bash Environment Variable Injection (Metasploit)remote, 2 Oct 2017, verified by Exploit-DB
- RedStar 3.0 Server - 'Shellshock' 'BEAM' / 'RSSMON' Command Injectionlocal, 18 Dec 2016, verified by Exploit-DB
- TrendMicro InterScan Web Security Virtual Appliance - 'Shellshock' Remote Command Injectionremote, 21 Oct 2016
- IPFire - 'Shellshock' Bash Environment Variable Command Injection (Metasploit)remote, 10 Jun 2016, verified by Exploit-DB
Metasploit
- exploit/linux/http/advantech_switch_bash_env_execexploit, rank excellent
- exploit/linux/http/ipfire_bashbug_execexploit, rank excellent
- exploit/multi/ftp/pureftpd_bash_env_execexploit, rank excellent
- exploit/multi/http/apache_mod_cgi_bash_env_execexploit, rank excellent
Nuclei
- ShellShock - Remote Code Executiondetection template, critical
GitHub proofs of concept
- opsxcq/exploit-CVE-2014-6271232 stars
- scottjpack/shellshock_scanner46 stars
- hmlio/vaas-cve-2014-627122 stars
- b4keSn4ke/CVE-2014-627115 stars
and 92 more repositories
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 24 Sept 2014First public exploit or proof of concept
- 24 Sept 2014Published1 day later
- 28 Jan 2022Added to CISA KEV (exploited in the wild)2,682 days (about 7 years) later
- 28 Jul 2022CISA remediation due date (US federal agencies)181 days (about 6 months) later
- 7 Feb 2025CISA SSVC assessment: exploitation active926 days (about 3 years) later
- 22 Oct 2025CVE record last updated256 days (about 9 months) later
- 12 Nov 2026Analysed by vulneraibility.com387 days (about 1 year) later
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
| Metric | Value | What it means |
|---|---|---|
| Attack vector | NetworkReachable over the internet or any routable network. | Reachable over the internet or any routable network. |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | NoneThe attacker needs no prior access. | The attacker needs no prior access. |
| User interaction | NoneNo victim action needed. | No victim action needed. |
| Scope | UnchangedImpact stays within the vulnerable component. | Impact stays within the vulnerable component. |
| Confidentiality | HighTotal data disclosure possible. | Total data disclosure possible. |
| Integrity | HighComplete modification possible. | Complete modification possible. |
| Availability | HighFull outage possible. | Full outage possible. |
Common questions
Is CVE-2014-6271 being exploited?
Yes. CVE-2014-6271 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2014-6271?
CVE-2014-6271 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2014-6271?
Yes. A fix has been recorded for CVE-2014-6271. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2014-6271 affect?
CVE-2014-6271 affects gnu:bash, arista:eos, oracle:linux, qnap:qts, and 26 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
50 references in the CVE record, grouped by the tags the record gives them.
Advisories (31)
- lists.opensuse.org /opensuse-security-announce/2014-09/msg00034.html
- marc.info /?l=bugtraq&m=141577137423233&w=2
- marc.info /?l=bugtraq&m=142719845423222&w=2
- marc.info /?l=bugtraq&m=141216668515282&w=2
- rhn.redhat.com /errata/RHSA-2014-1295.html
- lists.opensuse.org /opensuse-security-announce/2014-09/msg00037.html
Show 25 more
- marc.info /?l=bugtraq&m=141383138121313&w=2
- marc.info /?l=bugtraq&m=142721162228379&w=2
- marc.info /?l=bugtraq&m=142358026505815&w=2
- secunia.com /advisories/61188
- jvn.jp /en/jp/JVN55667175/index.html
- secunia.com /advisories/61676
- lists.opensuse.org /opensuse-security-announce/2014-09/msg00044.html
- secunia.com /advisories/60433
- marc.info /?l=bugtraq&m=141383026420882&w=2
- marc.info /?l=bugtraq&m=141585637922673&w=2
- lists.opensuse.org /opensuse-security-announce/2014-09/msg00049.html
- marc.info /?l=bugtraq&m=141576728022234&w=2
- secunia.com /advisories/61715
- secunia.com /advisories/61816
- lists.opensuse.org /opensuse-updates/2014-10/msg00025.html
- secunia.com /advisories/61442
- marc.info /?l=bugtraq&m=142358078406056&w=2
- marc.info /?l=bugtraq&m=142805027510172&w=2
- secunia.com /advisories/61283
- marc.info /?l=bugtraq&m=142113462216480&w=2
- ubuntu.com /usn/USN-2362-1
- lists.opensuse.org /opensuse-updates/2014-10/msg00023.html
- secunia.com /advisories/61654
- secunia.com /advisories/61542
- secunia.com /advisories/62312
Exploits (4)
- exploit-db.com /exploits/37816/
- exploit-db.com /exploits/39918/
- exploit-db.com /exploits/40619/
- exploit-db.com /exploits/38849/
Other links (15)
- packetstormsecurity.com /files/128517/VMware-Security-Advisory-2014-0010.html
- www-01.ibm.com /support/docview.wss?uid=ssg1S1004897
- www-01.ibm.com /support/docview.wss?uid=swg21685749
- securityblog.redhat.com /2014/09/24/bash-specially-crafted-environment-variables-code-injection-attack/
- supportcenter.checkpoint.com /supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk102673&s
- securityfocus.com /archive/1/533593/100/0/threaded
Show 9 more
- www-01.ibm.com /support/docview.wss?uid=swg21686084
- www-01.ibm.com /support/docview.wss?uid=swg21686479
- websense.com /support/article/kbarticle/Vulnerabilities-resolved-in-TRITON-APX-Version-8-0
- kb.juniper.net /InfoCenter/index?page=content&id=JSA10673
- www-01.ibm.com /support/docview.wss?uid=swg21685541
- oracle.com /technetwork/topics/security/bashcve-2014-7169-2317675.html
- kc.mcafee.com /corporate/index?page=content&id=SB10085
- novell.com /support/kb/doc.php?id=7015701
- www-947.ibm.com /support/entry/portal/docdisplay?lndocid=MIGR-5096315
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Exploit-DB: published exploits
- Metasploit Framework: exploit and scanner modules
- Nuclei templates: detection templates
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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