Mantis before 1.1.0a2 does not implement per-item access control for Issue History (Bug History), which allows remote attackers to obtain sensitive information by reading the Change column, as demonstrated by the Change column of a custom field.
https://exchange.xforce.ibmcloud.com/vulnerabilities/30870
http://www.vupen.com/english/advisories/2006/4978
http://www.securityfocus.com/bid/21566
http://www.mantisbugtracker.com/changelog.php
http://www.debian.org/security/2008/dsa-1467
http://sourceforge.net/project/shownotes.php?release_id=469627
http://secunia.com/advisories/28551
http://secunia.com/advisories/23258
http://mantisbt.cvs.sourceforge.net/mantisbt/mantisbt/core/history_api.php?view=log
http://mantisbt.cvs.sourceforge.net/mantisbt/mantisbt/core/history_api.php?r1=1.34&r2=1.35