The msn_httpconn_parse_data function in httpconn.c in the MSN protocol plugin in libpurple in Pidgin before 2.10.0 does not properly handle HTTP 100 responses, which allows remote attackers to cause a denial of service (incorrect memory access and application crash) via vectors involving a crafted server message.

Marius Wachtler discovered that Pidgin incorrectly handled malformed YMSG messages in the Yahoo! protocol handler. A remote attacker could send a specially crafted message and cause Pidgin to crash, leading to a denial of service. This issue only affected Ubuntu 10.04 LTS and 10.10. (CVE-2011-1091)

Marius Wachtler discovered that Pidgin incorrectly handled HTTP 100 responses in the MSN protocol handler. A remote attacker could send a specially crafted message and cause Pidgin to crash, leading to a denial of service. (CVE-2011-3184)

Diego Bauche Madero discovered that Pidgin incorrectly handled UTF-8 sequences in the SILC protocol handler. A remote attacker could send a specially crafted message and cause Pidgin to crash, leading to a denial of service. (CVE-2011-3594).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Multiple vulnerabilities has been identified and fixed in pidgin :

It was found that the gdk-pixbuf GIF image loader routine gdk_pixbuf__gif_image_load() did not properly handle certain return values from its subroutines. A remote attacker could provide a specially crafted GIF image, which, once opened in Pidgin, would lead gdk-pixbuf to return a partially initialized pixbuf structure. Using this structure, possibly containing a huge width and height, could lead to the application being terminated due to excessive memory use (CVE-2011-2485).

Certain characters in the nicknames of IRC users can trigger a NULL pointer dereference in the IRC protocol plugin's handling of responses to WHO requests. This can cause a crash on some operating systems.
Clients based on libpurple 2.8.0 through 2.9.0 are affected (CVE-2011-2943).

Incorrect handling of HTTP 100 responses in the MSN protocol plugin can cause the application to attempt to access memory that it does not have access to. This only affects users who have turned on the HTTP connection method for their accounts (it's off by default). This might only be triggerable by a malicious server and not a malicious peer. We believe remote code execution is not possible (CVE-2011-3184).

This update provides pidgin 2.10.0, which is not vulnerable to these issues.

New release 2.10.0

Full Upstream ChangeLog :

http://developer.pidgin.im/wiki/ChangeLog

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.

The version of Pidgin installed on the remote host is earlier than 2.10.0.  As such, it is potentially affected by the following issues :

  - A code execution vulnerability caused by clicking on a     file:// URI received in an IM that Pidgin will attempt     to execute.  This can result in the execution of     attacker-controlled code if the file is located on a     network share. (CVE-2011-3185)

  - A denial of service in the IRC protocol plugin caused     by processing a specially crafted nickname when listing     the set of users. (CVE-2011-2943)

  - A denial of service in the MSN protocol plugin caused     by incorrect handling of HTTP 100 responses.  This only     affects users who have enabled the HTTP connection     method, which is disabled by default. (CVE-2011-3184)

ID	Name	Product	Family	Severity
56915	Ubuntu 10.04 LTS / 10.10 / 11.04 : pidgin vulnerabilities (USN-1273-1)	Nessus	Ubuntu Local Security Checks	medium
56109	Mandriva Linux Security Advisory : pidgin (MDVSA-2011:132-1)	Nessus	Mandriva Local Security Checks	medium
56101	Fedora 14 : pidgin-2.10.0-1.fc14 (2011-11595)	Nessus	Fedora Local Security Checks	medium
56015	Fedora 15 : pidgin-2.10.0-1.fc15 (2011-11544)	Nessus	Fedora Local Security Checks	medium
55928	Pidgin < 2.10.0 Multiple Vulnerabilities	Nessus	Windows	high

Detections

Analytics

CVE-2011-3184

high

Tenable Plugins

medium

medium

medium

medium

high