teTeX is a complete TeX distribution for editing documents.
Mark Richters discovered a buffer overflow in the open_sty() function in file mkind.c. Other vulnerabilities have also been discovered in the same file but might not be exploitable (CVE-2007-0650). Tetex also includes vulnerable code from GD library (GLSA 200708-05), and from Xpdf (CVE-2007-3387).
A remote attacker could entice a user to process a specially crafted PNG, GIF or PDF file, or to execute "makeindex" on an overly long filename. In both cases, this could lead to the remote execution of arbitrary code with the privileges of the user running the application.
There is no known workaround at this time.
All teTeX users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=app-text/tetex-3.0_p1-r4"