Cyber Resilience

CVE-2011-2523

RCE in Debian Linux 10.0 … 9.0

Public PoCHigh EPSSRCECommand Injection
Published
27 November 2019
Modified
21 November 2024
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.96 99.9th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2011-2523 is a critical-severity OS Command Injection (CWE-78) vulnerability in Debian Debian Linux. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 0.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

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

CWE(s)
CWE-78

Related Threats

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1190 Exploit Public-Facing Application Initial Accessconfidence: HIGH
The backdoor in the publicly downloadable vsftpd binary directly enables remote code execution via exploitation of a public-facing FTP service.
attack.mitre.org →
T1059.004 Unix Shell Executionconfidence: HIGH
The backdoor opens an interactive Unix shell on TCP port 6200, allowing command execution through the Unix shell.
attack.mitre.org →
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2023-51385Same product: Debian Debian Linux
CVE-2024-10224Same product: Debian Debian Linux
CVE-2018-7187Same product: Debian Debian Linux
CVE-2025-63261Same product: Debian Debian Linux
CVE-2023-24805Same product: Debian Debian Linux
CVE-2019-10149Same product: Debian Debian Linux
CVE-2020-16846Same product: Debian Debian Linux
CVE-2017-17405Same product: Debian Debian Linux
CVE-2020-8813Same product: Debian Debian Linux
CVE-2020-26217Same product: Debian Debian Linux

Affected Assets

vsftpd project
vsftpd
2.3.4
debian
debian linux
10.0, 8.0, 9.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.5
  • V1.2.8
  • V15.2.5

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

SI-10 Information Input Validation
addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
detects

Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

References