libpng heap based buffer overflow There is a heap based buffer overflow in libpng 1.2.7 only. Upstream has a note with the release for 1.2.8 that fixes a crash when a program tries to strip alpha channels out of the image (calling the png_set_strip_alpha() function during libpng initialization). It should be noted that this particular libpng feature is only used by tetex and xemacs within RHEL4, limiting the potential damage the overflow can cause.
Created attachment 123913 [details] Patch extracted from the upstream 1.2.8 release
Created attachment 123914 [details] Testcase
I have built libpng-1.2.7-1.el4.2 with the patch, and converted your testcase in the RHTS test /desktop/libpng/CVE2006-0481, but it doesn't work in RHTS for some reason. Local testing yields the expected results.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2006-0205.html