JRequest in Joomla! 1.5 before 1.5.7 does not sanitize variables that were set with JRequest::setVar, which allows remote attackers to conduct "variable injection" attacks and have unspecified other impact.
Joomla! before 1.5.4 allows attackers to access administration functionality, which has unknown impact and attack vectors related to a missing "LDAP security fix."
Unspecified vulnerability in Joomla! before 1.5.4 has unknown impact and attack vectors related to a "User Redirect Spam fix," possibly an open redirect vulnerability.
Joomla! before 1.5.4 does not configure .htaccess to apply certain security checks that "block common exploits" to SEF URLs, which has unknown impact and remote attack vectors.