A Denial-of-Service flaw was found in the OpenStack Networking (neutron) L2 agent when using the iptables firewall driver. By submitting an address pair that is rejected as invalid by the ipset tool (with zero prefix size), an authenticated attacker can cause the L2 agent to crash.
DescriptionVasyl Kaigorodov
2015-06-16 12:27:30 UTC
Title: Neutron L2 agent DoS through incorrect allowed address pairs
Reporter: Darragh O'Reilly (HP)
Products: Neutron
Affects: 2014.2 versions through 2014.2.3 and 2015.1.0 version
Description:
Darragh O'Reilly from HP reported a vulnerability in Neutron. By adding
an address pair which is rejected as invalid by the ipset tool, an
authenticated user may crash the Neutron L2 agent resulting in a denial
of service attack. Neutron setups using the IPTables firewall driver are
affected.
Acknowledgements:
Red Hat would like to thank the OpenStack upstream for reporting this issue. Upstream acknowledges Darragh O'Reilly (HP) as the original reporter.
Comment 6Tristan Cacqueray
2015-06-19 20:10:57 UTC
Some more notes, the kilo and liberty patch are self healing, if a zero prefixed address pair have already been assigned, then it will be fixed when the service restarts.
Juno patch on the other hand will block attempt to use zero prefixed address pair and if a zero prefixed address pair have already been assigned, then the script included in the patch needs to be run in order to fix it.