Oracle Linux: CVE-2019-3883: ELSA-2019-1896: 389-ds-base security and bug fix update (MODERATE) (Multiple Advisories)

In 389-ds-base up to version 1.4.1.2, requests are handled by workers threads. Each sockets will be waited by the worker for at most 'ioblocktimeout' seconds. However this timeout applies only for un-encrypted requests. Connections using SSL/TLS are not taking this timeout into account during reads, and may hang longer.An unauthenticated attacker could repeatedly create hanging LDAP requests to hang all the workers, resulting in a Denial of Service.
It was found that encrypted connections did not honor the 'ioblocktimeout' parameter to end blocking requests. As a result, an unauthenticated attacker could repeatedly start a sufficient number of encrypted connections to block all workers, resulting in a denial of service.