In OpenLDAP 2.x before 2.5.12 and 2.6.x before 2.6.2, a SQL injection vulnerability exists in the experimental back-sql backend to slapd, via a SQL statement within an LDAP query. This can occur during an LDAP search operation when the search filter is processed, due to a lack of proper escaping.
A bug in slapd's UTF8StringNormalize() function can cause a one-byte buffer overflow when it is passed a zero-length string. The code then writes a '\0' past the one-byte long buffer allocated on the heap, which could possibly allow a remote authenticated user to crash slapd. As per the upstream report [1], this bug has been present since 2003-04-07 [2] so should affect all versions of openldap we currently ship.
A patch to correct the flaw has been committed [3] (depends on the previous patch [4]).
[1] http://www.openldap.org/its/index.cgi/Software%20Bugs?id=7059;selectid=7059 [2] http://www.openldap.org/devel/gitweb.cgi?p=openldap.git;a=commitdiff;h=67d6b23d [3] http://www.openldap.org/devel/gitweb.cgi?p=openldap.git;a=commitdiff;h=507238713b71208ec4f262f312cb495a302df9e9 [4] http://www.openldap.org/devel/gitweb.cgi?p=openldap.git;a=commitdiff;h=d0dd8616f1c68a868afeb8c2c5c09969e366e2c0