HOME VULNERABILITIESCVE-2011-2523

CRITICALPOC

CVE-2011-2523

CWE-78Published: November 27, 2019· Updated: Jun 16, 2026

9.8

CVSS v3.1

Official Description

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

Technical Analysis

CVE-2011-2523 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

A proof-of-concept (PoC) exploit exists for CVE-2011-2523. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Debian1 product(s)

debian linux

vsftpd_project1 product(s)

vsftpd

Source: NVD CPE · 4 total CPE entries

Exploit & PoC Resources

POC AVAILABLEProof-of-concept code exists

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

Security advisories & exploits

Official NIST entry

CVE Program entry

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://access.redhat.com/security/cve/cve-2011-2523

ADVISORYhttps://packetstormsecurity.com/files/102745/VSFTPD-2.3.4-Backdoor-Command-Execution.html

ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2011-2523

ADVISORYhttps://vigilance.fr/vulnerability/vsftpd-backdoor-in-version-2-3-4-10805

ADVISORYhttps://www.openwall.com/lists/oss-security/2011/07/11/5

ADVISORYhttps://access.redhat.com/security/cve/cve-2011-2523

ADVISORYhttps://packetstormsecurity.com/files/102745/VSFTPD-2.3.4-Backdoor-Command-Execution.html

ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2011-2523

ADVISORYhttps://vigilance.fr/vulnerability/vsftpd-backdoor-in-version-2-3-4-10805

ADVISORYhttps://www.openwall.com/lists/oss-security/2011/07/11/5

All References (12)

→

http://packetstormsecurity.com/files/162145/vsftpd-2.3.4-Backdoor-Command-Execution.html

→

https://access.redhat.com/security/cve/cve-2011-2523Third Party Advisory

→

https://packetstormsecurity.com/files/102745/VSFTPD-2.3.4-Backdoor-Command-Execution.htmlExploit · Third Party Advisory · VDB Entry

→

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 List · Third Party Advisory

→

http://packetstormsecurity.com/files/162145/vsftpd-2.3.4-Backdoor-Command-Execution.html

→

https://access.redhat.com/security/cve/cve-2011-2523Third Party Advisory

→

https://packetstormsecurity.com/files/102745/VSFTPD-2.3.4-Backdoor-Command-Execution.htmlExploit · Third Party Advisory · VDB Entry

→

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 List · Third Party Advisory

Quick Facts

CVE IDCVE-2011-2523

CVSS Score9.8 / 10

SeverityCRITICAL

WeaknessCWE-78

CISA KEVNo

ExploitPOC

Affected2 vendor(s)

PublishedNov 27, 2019

Related CVEs (CWE-78)

Recommended Actions

→Apply vendor patches immediately
→Monitor CVE-2011-2523 in threat intel feeds
→Review IDS/IPS signatures for exploitation attempts

Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.

← All Vulnerabilities·Search for CVE-2011-2523·NVD