Lynx is a text-mode browser for the World Wide Web. It supports multiple URL types, including HTTP and NNTP URLs.
When accessing a NNTP URL, Lynx connects to a NNTP server and retrieves information about the available articles in the target newsgroup. Ulf Harnhammar discovered a buffer overflow in a function that handles the escaping of special characters.
An attacker could setup a malicious NNTP server and entice a user to access it using Lynx (either by creating NNTP links on a web page or by forcing a redirect for Lynx users). The data returned by the NNTP server would trigger the buffer overflow and execute arbitrary code with the rights of the user running Lynx.
There is no known workaround at this time.
All Lynx users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=www-client/lynx-2.8.5-r1"