CVE-2009-2936

Varnish < 2.1.0 - Unauthenticated Remote Code Execution via CLI vcl.inline Directive

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 3 public exploits for CVE-2009-2936. PoCs published by Patrick Webster, patrick, h00die <[email protected]>, aushack, h00die <[email protected]>, including Metasploit module auxiliary/scanner/varnish/varnish_cli_file_read.

AI-analyzed exploit summary This Metasploit module exploits CVE-2009-2936 by brute-forcing the Varnish Cache CLI interface to gain unauthorized access. Upon successful authentication, it attempts to read the /etc/shadow file to extract the root password hash.

Description

The Command Line Interface (aka Server CLI or administration interface) in the master process in the reverse proxy server in Varnish before 2.1.0 does not require authentication for commands received through a TCP port, which allows remote attackers to (1) execute arbitrary code via a vcl.inline directive that provides a VCL configuration file containing inline C code; (2) change the ownership of the master process via param.set, stop, and start directives; (3) read the initial line of an arbitrary file via a vcl.load directive; or (4) conduct cross-site request forgery (CSRF) attacks that leverage a victim's location on a trusted network and improper input validation of directives. NOTE: the vendor disputes this report, saying that it is "fundamentally misguided and pointless.

Exploits (3)

exploitdb WORKING POC
by Patrick Webster · rubyremotelinux
https://www.exploit-db.com/exploits/35581

This Metasploit module exploits CVE-2009-2936 by brute-forcing the Varnish Cache CLI interface to gain unauthorized access. Upon successful authentication, it attempts to read the /etc/shadow file to extract the root password hash.

Classification
Working Poc 90%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: Varnish Cache (varnishd) CLI interface
Auth required
Prerequisites: Network access to the Varnish Cache CLI interface (default port 6082) · A wordlist of potential passwords
MITRE ATT&CK
devstral-2 · analyzed Feb 16, 2026 Full analysis →
metasploit WORKING POC
by patrick, h00die <[email protected]> · rubypoc
https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/scanner/varnish/varnish_cli_file_read.rb

This Metasploit module exploits a file read vulnerability in Varnish Cache CLI by abusing the error message when compiling a file with vcl.load. It attempts to read the first line of a specified file, such as /etc/passwd, by leveraging the debug message returned upon failure.

Classification
Working Poc 95%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: Varnish Cache (versions affected by CVE-2009-2936)
No auth needed
Prerequisites: Network access to the Varnish CLI port (default 6082) · Varnish Cache CLI accessible without authentication or with known credentials
devstral-2 · analyzed Feb 16, 2026 Full analysis →
metasploit SCANNER
by aushack, h00die <[email protected]> · rubypoc
https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/scanner/varnish/varnish_cli_login.rb

This Metasploit module attempts to brute-force login to the Varnish Cache CLI by testing passwords from a provided wordlist. It checks if authentication is required and reports successful logins.

Classification
Scanner 100%
Attack Type
Auth Bypass
Complexity
Trivial
Reliability
Reliable
Target: Varnish Cache (varnishd) CLI
No auth needed
Prerequisites: Network access to the Varnish CLI port (default 6082) · A wordlist of passwords
MITRE ATT&CK
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (5)

Core 5
Core References
Third Party Advisory, VDB Entry mailing-list x_refsource_bugtraq
http://www.securityfocus.com/archive/1/510360/100/0/threaded
Third Party Advisory x_refsource_misc
http://www.varnish-cache.org/wiki/CLI
Various Sources x_refsource_misc
http://www.varnish-cache.org/changeset/3865
Third Party Advisory, VDB Entry mailing-list x_refsource_bugtraq
http://www.securityfocus.com/archive/1/510368/100/0/threaded
Mailing List, Third Party Advisory vendor-advisory x_refsource_fedora
http://lists.fedoraproject.org/pipermail/package-announce/2010-April/040359.html

Scores

EPSS 0.6382
EPSS Percentile 99.1%

Details

CWE
CWE-287
Status published
Products (17)
varnish.projects.linpro/varnish 0.9
varnish.projects.linpro/varnish 0.9.1
varnish.projects.linpro/varnish 1.0
varnish.projects.linpro/varnish 1.0.1
varnish.projects.linpro/varnish 1.0.2
varnish.projects.linpro/varnish 1.0.3
varnish.projects.linpro/varnish 1.0.4
varnish.projects.linpro/varnish 1.1
varnish.projects.linpro/varnish 1.1.1
varnish.projects.linpro/varnish 1.1.2
... and 7 more
Published Apr 05, 2010
Tracked Since Feb 18, 2026