The Microsoft .NET forms authentication capability for ASP.NET allows remote attackers to bypass authentication for .aspx files in restricted directories via a request containing a (1) "" (backslash) or (2) “%5C” (encoded backslash), aka “Path Validation Vulnerability.”
archives.neohapsis.com/archives/ntbugtraq/2004-q3/0221.html
sourceforge.net/mailarchive/forum.php?thread_id=5671607&forum_id=24754
www.kb.cert.org/vuls/id/283646
www.securityfocus.com/bid/11342
www.us-cert.gov/cas/techalerts/TA05-039A.html
docs.microsoft.com/en-us/security-updates/securitybulletins/2005/ms05-004
exchange.xforce.ibmcloud.com/vulnerabilities/17644
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A3556
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A4987