ViewVC before 1.1.11 allows remote attackers to bypass the cvsdb row_limit configuration setting, and consequently conduct resource-consumption attacks, via the limit parameter, as demonstrated by a "query revision history" request.
http://www.securityfocus.com/bid/47928
http://www.debian.org/security/2012/dsa-2563
http://viewvc.tigris.org/source/browse/viewvc/trunk/lib/cvsdb.py?diff_format=u&view=log#rev2547
http://viewvc.tigris.org/source/browse/%2Acheckout%2A/viewvc/tags/1.1.11/CHANGES
http://viewvc.tigris.org/issues/show_bug.cgi?id=433