Multiple vulnerabilities has been discovered and corrected in openldap:

The slap_modrdn2mods function in modrdn.c in OpenLDAP 2.4.22 does not
check the return value of a call to the smr_normalize function, which
allows remote attackers to cause a denial of service (segmentation
fault) and possibly execute arbitrary code via a modrdn call with an
RDN string containing invalid UTF-8 sequences, which triggers a free
of an invalid, uninitialized pointer in the slap_mods_free function, as
demonstrated using the Codenomicon LDAPv3 test suite (CVE-2010-0211).

OpenLDAP 2.4.22 allows remote attackers to cause a denial of service
(crash) via a modrdn call with a zero-length RDN destination string,
which is not properly handled by the smr_normalize function and
triggers a NULL pointer dereference in the IA5StringNormalize function
in schema_init.c, as demonstrated using the Codenomicon LDAPv3 test
suite (CVE-2010-0212).

Packages for 2008.0 and 2009.0 are provided as of the Extended
Maintenance Program. Please visit this link to learn more:
http://store.mandriva.com/product_info.php?cPath=149&products_id=490

The updated packages have been patched to correct these issues.