The “Extended properties for entries” (entryproperties) plugin in serendipity_event_entryproperties.php in Serendipity 1.1.3 allows remote authenticated users to bypass password protection and “deliver custom entryproperties settings to the Serendipity Frontend” via a certain request that modifies the password being checked.
blog.drinsama.de/erich/en/security/2007080801-security-issue-in-serendipity.html
blog.s9y.org/archives/178-Serendipity-1.1.4-released%2C-security-bug-in-entryproperties-plugin.html
osvdb.org/36534
secunia.com/advisories/26347
sourceforge.net/forum/forum.php?forum_id=722867
sourceforge.net/project/shownotes.php?group_id=75065&release_id=530716
www.securityfocus.com/bid/25235
exchange.xforce.ibmcloud.com/vulnerabilities/35868