slapo-pcache (overlays/pcache.c) in slapd in OpenLDAP before 2.3.39, when running as a proxy-caching server, allocates memory using a malloc variant instead of calloc, which prevents an array from being initialized properly and might allow attackers to cause a denial of service (segmentation fault) via unknown vectors that prevent the array from being null terminated.
http://www.vupen.com/english/advisories/2007/3645
http://www.ubuntu.com/usn/usn-551-1
http://www.securityfocus.com/bid/26245
http://www.redhat.com/archives/fedora-package-announce/2007-November/msg00460.html
http://www.openldap.org/lists/openldap-announce/200710/msg00001.html
http://www.openldap.org/its/index.cgi/Software%20Bugs?id=5163
http://www.novell.com/linux/security/advisories/2007_24_sr.html
http://www.mandriva.com/security/advisories?name=MDVSA-2008:058
http://www.debian.org/security/2008/dsa-1541
http://security.gentoo.org/glsa/glsa-200803-28.xml
http://secunia.com/advisories/29682
http://secunia.com/advisories/29461
http://secunia.com/advisories/29225
http://secunia.com/advisories/27868
http://secunia.com/advisories/27756