Home/CVE/vsftpd 2.3.4 downloaded between 20110630 and 20110703 contains a backdoor which opens a shell on port 6200/tcp.
CVE

CVE-2011-2523

vsftpd 2.3.4 downloaded between 20110630 and 20110703 contains a backdoor which opens a shell on port 6200/tcp.

vsftpd 2.3.4 downloaded between 20110630 and 20110703 contains a backdoor which opens a shell on port 6200/tcp.

CRITICAL · CVSS 9.8 EPSS 0.94282
Act now
  • EPSS ≥ 0.50 - high probability of exploitation in the next 30 days
  • EPSS percentile: top 0% of all CVEs by exploitation likelihood
  • Public exploit or PoC is available
  • CVSS base score ≥ 7.0
Sigma rules1 YARA rules0
⬡

Weakness Classification

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
▤

Affected Products & Versions

2
vsftpd project vsftpdall versions
debian linuxall versions
⚠

Public Exploits & PoCs

5
remotevsftpd 2.3.4 - Backdoor Command Executionverified
remotevsftpd 2.3.4 - Backdoor Command Execution (Metasploit)verified
nucleiVSFTPD 2.3.4 - Backdoor Command Executioncritical
pocpacketstormsecurity.com · vsftpd-2.3.4-Backdoor-Command-Execution.htmlpacketstormsecurity.com
pocpacketstormsecurity.com · VSFTPD-2.3.4-Backdoor-Command-Execution.htmlpacketstormsecurity.com
◈

Sigma Hunt Rules

1
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
productmediumSuspicious VSFTPD Error Messages
▣

Scoring & Timeline

9.8
CRITICAL · CVSS v3.1 · secalert@redhat.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD27 Nov 2019 · 09:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
🔗

References & Sources

4
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://access.redhat.com/security/cve/cve-2011-2523Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2011-2523Third Party Advisory
https://vigilance.fr/vulnerability/vsftpd-backdoor-in-version-2-3-4-10805Third Party Advisory
https://www.openwall.com/lists/oss-security/2011/07/11/5Mailing ListThird Party Advisory
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