Multiple versions of OpenLDAP contain vulnerabilities that may allow denial-of-service attacks. These vulnerabilities were revealed using the PROTOS LDAPv3 test suite and are documented in CERT Advisory CA-2001-18. If your site uses this product, the CERT/CC encourages you to follow the advice provided below.
There are multiple vulnerabilities in the OpenLDAP implementations of the LDAP protocol. These vulnerabilities exist in the code that translates network datagrams into application-specific information.
In the encoding section of the test suite, this product failed the group that tests the handling of invalid BER length of length fields.
These vulnerabilities allow a remote attacker to crash affected OpenLDAP servers, resulting in a denial-of-service condition.
Apply a patch from your vendor
Block access to directory services at network perimeter
The CERT Coordination Center thanks the Oulu University Secure Programming Group for reporting these vulnerabilities to us, for their detailed technical analyses, and for their assistance in preparing this document. We would also like to thank the OpenLDAP Core Team for their assistance in preparing this document.