print_all_bug_page.php in Mantis 0.17.3 and earlier does not verify the limit_reporters option, which allows remote attackers to view bug summaries for bugs that would otherwise be restricted.
https://exchange.xforce.ibmcloud.com/vulnerabilities/9898
http://www.securityfocus.com/bid/5515
http://www.debian.org/security/2002/dsa-153