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Public proof of concept

CVE-2011-2523

A public proof of concept exists; no exploitation attested.

  • Published2019-11-27
  • WeaknessCWE-78

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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

Timeline

dates in UTC
  1. 2011-07-05Exploit-DB entryExploit-DB
  2. 2019-11-2721:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-11-04 03:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2011-2523?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2011-2523?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Debian debian linux
BranchAffectedFixed in
8.0= 8.0no fix published
9.0= 9.0no fix published
10.0= 10.0no fix published
Vsftpd project vsftpd
BranchAffectedFixed in
2.3= 2.3.4no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2011-2523 Red Hat Product Security

    vsftpd: backdoor which opens a shell on port 6200/tcp

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

read 2026-11-03 22:42 UTC
Nuclei template
available
ProjectDiscovery
Exploit-DB
EDB-17491EDB-49757
Exploit-DB
Proof-of-concept repositories
20 repositories, unverifiedHerculesRD/vsftpd2.3.4PyExploitnobodyatall648/CVE-2011-2523Gr4ykt/CVE-2011-2523padsalatushal/CVE-2011-2523MFernstrom/OffensivePascal-CVE-2011-2523
PoC-in-GitHub
Metasploit modules
1 moduleexploit/unix/ftp/vsftpd_234_backdoorrank: excellentModule metadata: Metasploit Framework, © Rapid7, Inc., BSD-3-Clause.
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2019-11-27
Last Modified
2026-06-16
NVD status
Modified

Frequently asked questions

What is CVE-2011-2523?

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

Is CVE-2011-2523 actively exploited?

Active exploitation of CVE-2011-2523 has not been confirmed. Its EPSS score was 96.2% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2011-2523?

CVE-2011-2523 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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Same product first, then the same vendor advisory and the same publication week.

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Sources for this record