XAPI open file limit DoS

ISSUE DESCRIPTION

It is possible for an unauthenticated client on the network to cause XAPI to hit its file-descriptor limit. This causes XAPI to be unable to accept new requests for other (trusted) clients, and blocks XAPI from carrying out any tasks that require the opening of file descriptors.

IMPACT

An attacker is capable of blocking connections to the XAPI HTTP interface, and also interrupt ongoing operations, causing a XAPI toolstack Denial of Service. Such DoS would also affect any guests that require toolstack actions.

VULNERABLE SYSTEMS

All versions of XAPI are vulnerable.
Systems which are not using the XAPI toolstack are not vulnerable.