Lynx: Arbitrary command execution

Background

Lynx is a fully-featured WWW client for users running cursor-addressable, character-cell display devices such as vt100 terminals and terminal emulators.

Description

Clint Ruoho reported that the fix for CVE-2005-2929 (GLSA 200511-09) only disabled the lynxcgi:// handler when not using the advanced mode.

Impact

A remote attacker can entice a user to access a malicious HTTP server, causing Lynx to execute arbitrary commands. NOTE: The advanced mode is not enabled by default. Successful exploitation requires the “lynxcgi://” protocol to be registered with lynx on the victim’s system.

Workaround

There is no known workaround at this time.

Resolution

All Lynx users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=www-client/lynx-2.8.6-r4"