Red Hat Enterprise Linux 7: RHSA-2016-0204-01 Critical: DoS in 389-Ds-Base

The 389 Directory Server is an LDAP version 3 (LDAPv3) compliant server. The base packages include the Lightweight Directory Access Protocol (LDAP) server and command-line utilities for server administration.
An infinite-loop vulnerability was discovered in the 389 directory server, where the server failed to correctly handle unexpectedly closed client connections. A remote attacker able to connect to the server could use this flaw to make the directory server consume an excessive amount of CPU and stop accepting connections (denial of service). (CVE-2016-0741)
This update fixes the following bugs:
* Previously, if a simple paged results search failed in the back end, the simple paged results slot was not released. Consequently, the simple paged results slots in a connection object could be accumulated. With this update, the simple paged results slot is released correctly when a search fails, and unused simple paged results slots are no longer left in a connection object. (BZ#1290725)
* Previously, when several values of the same attribute were deleted using the ldapmodify command, and at least one of them was added again during the same operation, the equality index was not updated. As a consequence, an exact search for the re-added attribute value did not return the entry. The logic of the index code has been modified to update the index if at least one of the values in the entry changes, and the exact search for the re-added attribute value now returns the correct entry. (BZ#1290726)
* Prior to this update, when the cleanAllRUV task was running, a bogus attrlist_replace error message was logged repeatedly due to a memory corruption. With this update, the appropriate memory copy function memmove is used, which fixes the memory corruption. As a result, the error messages are no longer logged in this scenario. (BZ#1295684)
* To fix a simple paged results bug, an exclusive lock on a connection was previously added. This consequently caused a self deadlock in a particular case. With this update, the exclusive lock on a connection has been changed to the re-entrant type, and the self deadlock no longer occurs. (BZ#1298105)
* Previously, an unnecessary lock was sometimes acquired on a connection object, which could consequently cause a deadlock. A patch has been applied to remove the unnecessary locking, and the deadlock no longer occurs. (BZ#1299346)
Users of 389-ds-base are advised to upgrade to these updated packages, which correct these issues. After installing this update, the 389 server service will be restarted automatically.