389-ds-base: 389-ds-base: unauthenticated worker-thread-pool exhaustion via completed-operation-then-incomplete-pdu connection requeue
18Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5
exploitation probability
—
observed exploitation
nono source reports it
A flaw was found in 389-ds-base. An unauthenticated remote attacker can send a complete LDAP operation followed by the first bytes of an incomplete LDAPMessage on the same connection, causing the server to hand that connection to a second worker thread before the first worker's result is flushed. The second worker blocks until nsslapd-ioblocktimeout while holding the connection mutex, preventing delivery of the completed operation's result. Repeating this across a small number of connections proportional to the configured worker-thread pool size exhausts the entire pool under default configuration, denying service to all clients (anonymous and authenticated, plaintext and TLS) for as long as the attacker maintains the connections.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
Red Hat · Red Hat Directory Server 11Red Hat · Red Hat Directory Server 12Red Hat · Red Hat Directory Server 13Red Hat · Red Hat Enterprise Linux 10Red Hat · Red Hat Enterprise Linux 6Red Hat · Red Hat Enterprise Linux 7Red Hat · Red Hat Enterprise Linux 8Red Hat · Red Hat Enterprise Linux 9