The (1) libsasl and (2) libsasl2 libraries in Cyrus-SASL 2.1.18 and earlier trust the SASL_PATH environment variable to find all available SASL plug-ins, which allows local users to execute arbitrary code by modifying the SASL_PATH to point to malicious programs.
Buffer overflow in digestmd5.c CVS release 1.170 (also referred to as digestmda5.c), as used in the DIGEST-MD5 SASL plugin for Cyrus-SASL but not in any official releases, allows remote attackers to execute arbitrary code.
SQL injection vulnerability in the LDAP and MySQL authentication patch for Cyrus SASL 1.5.24 and 1.5.27 allows remote attackers to execute arbitrary SQL commands and log in as arbitrary POP mail users via the password.