ID CVE-2009-2936
Summary ** DISPUTED ** 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."
Vulnerable Configurations
  • cpe:2.3:a:varnish.projects.linpro:varnish:0.9
  • cpe:2.3:a:varnish.projects.linpro:varnish:0.9.1
  • cpe:2.3:a:varnish.projects.linpro:varnish:1.0
  • cpe:2.3:a:varnish.projects.linpro:varnish:1.0.1
  • cpe:2.3:a:varnish.projects.linpro:varnish:1.0.2
  • cpe:2.3:a:varnish.projects.linpro:varnish:1.0.3
  • cpe:2.3:a:varnish.projects.linpro:varnish:1.0.4
  • cpe:2.3:a:varnish.projects.linpro:varnish:1.1
  • cpe:2.3:a:varnish.projects.linpro:varnish:1.1.1
  • cpe:2.3:a:varnish.projects.linpro:varnish:1.1.2
  • cpe:2.3:a:varnish.projects.linpro:varnish:2.0
  • cpe:2.3:a:varnish.projects.linpro:varnish:2.0:beta1
  • cpe:2.3:a:varnish.projects.linpro:varnish:2.0:beta2
  • cpe:2.3:a:varnish.projects.linpro:varnish:2.0:rc1
  • cpe:2.3:a:varnish.projects.linpro:varnish:2.0.1
  • cpe:2.3:a:varnish.projects.linpro:varnish:2.0.2
  • cpe:2.3:a:varnish.projects.linpro:varnish:2.0.3
  • cpe:2.3:a:varnish.projects.linpro:varnish:2.0.4
  • cpe:2.3:a:varnish.projects.linpro:varnish:2.0.5
  • cpe:2.3:a:varnish.projects.linpro:varnish:2.0.6
Base: 7.5 (as of 06-04-2010 - 14:59)
  • Authentication Abuse
    An attacker obtains unauthorized access to an application, service or device either through knowledge of the inherent weaknesses of an authentication mechanism, or by exploiting a flaw in the authentication scheme's implementation. In such an attack an authentication mechanism is functioning but a carefully controlled sequence of events causes the mechanism to grant access to the attacker. This attack may exploit assumptions made by the target's authentication procedures, such as assumptions regarding trust relationships or assumptions regarding the generation of secret values. This attack differs from Authentication Bypass attacks in that Authentication Abuse allows the attacker to be certified as a valid user through illegitimate means, while Authentication Bypass allows the user to access protected material without ever being certified as an authenticated user. This attack does not rely on prior sessions established by successfully authenticating users, as relied upon for the "Exploitation of Session Variables, Resource IDs and other Trusted Credentials" attack patterns.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Utilizing REST's Trust in the System Resource to Register Man in the Middle
    This attack utilizes a REST(REpresentational State Transfer)-style applications' trust in the system resources and environment to place man in the middle once SSL is terminated. Rest applications premise is that they leverage existing infrastructure to deliver web services functionality. An example of this is a Rest application that uses HTTP Get methods and receives a HTTP response with an XML document. These Rest style web services are deployed on existing infrastructure such as Apache and IIS web servers with no SOAP stack required. Unfortunately from a security standpoint, there frequently is no interoperable identity security mechanism deployed, so Rest developers often fall back to SSL to deliver security. In large data centers, SSL is typically terminated at the edge of the network - at the firewall, load balancer, or router. Once the SSL is terminated the HTTP request is in the clear (unless developers have hashed or encrypted the values, but this is rare). The attacker can utilize a sniffer such as Wireshark to snapshot the credentials, such as username and password that are passed in the clear once SSL is terminated. Once the attacker gathers these credentials, they can submit requests to the web service provider just as authorized user do. There is not typically an authentication on the client side, beyond what is passed in the request itself so once this is compromised, then this is generally sufficient to compromise the service's authentication scheme.
  • Man in the Middle Attack
    This type of attack targets the communication between two components (typically client and server). The attacker places himself in the communication channel between the two components. Whenever one component attempts to communicate with the other (data flow, authentication challenges, etc.), the data first goes to the attacker, who has the opportunity to observe or alter it, and it is then passed on to the other component as if it was never intercepted. This interposition is transparent leaving the two compromised components unaware of the potential corruption or leakage of their communications. The potential for Man-in-the-Middle attacks yields an implicit lack of trust in communication or identify between two components.
exploit-db via4
description Varnish Cache CLI Interface - Remote Code Execution. CVE-2009-2936. Remote exploit for linux platform
id EDB-ID:35581
last seen 2016-02-04
modified 2014-12-19
published 2014-12-19
reporter Patrick Webster
title Varnish Cache CLI Interface - Remote Code Execution
metasploit via4
nessus via4
NASL family Fedora Local Security Checks
NASL id FEDORA_2010-6719.NASL
description Upgrade to new upstream release 2.1.0. This upgrade is important because - The previous 2.0 series will be discontinued within the lifetime of F-13 - 2.1.0 contains a fix for CVE-2009-2936. It is not probably that upstream will backport this fix for the 2.0 series These changes should be important enough to include varnish-2.1.x in F-13, even after the freeze. Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
last seen 2019-02-21
modified 2015-10-20
plugin id 47446
published 2010-07-01
reporter Tenable
title Fedora 13 : varnish-2.1.0-2.fc13 (2010-6719)
packetstorm via4
data source
last seen 2016-12-05
published 2014-12-20
reporter Patrick Webster
title Varnish Cache CLI Interface Remote Code Execution
refmap via4
  • 20100329 Medium security hole in Varnish reverse proxy
  • 20100329 Re: [Full-disclosure] Medium security hole in Varnish reverse proxy
fedora FEDORA-2010-6719
Last major update 06-05-2010 - 01:49
Published 05-04-2010 - 12:30
Last modified 10-10-2018 - 15:42
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