A denial of service flaw was found in the way Fetchmail, a remote mail retrieval and forwarding utility, performed base64 decoding of certain NTLM server responses. Upon sending the NTLM authentication request, Fetchmail did not check if the received response was actually part of NTLM protocol exchange, or server-side error message and session abort. A rogue NTML server could use this flaw to cause fetchmail executable crash.
Upstream advisory (not available yet):
This issue affects the versions of the fetchmail package, as shipped with Fedora release of 16 and 17. Please schedule an update.
Created fetchmail tracking bugs for this issue
Affects: fedora-all [bug 847989]
fetchmail-6.3.22-1.fc17 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report.