CVE-2018-17205
The assertion failure causes an OvS crash.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.53%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
An issue was discovered in Open vSwitch (OvS) 2.7.x through 2.7.6, affecting ofproto_rule_insert__ in ofproto/ofproto.c. During bundle commit, flows that are added in a bundle are applied to ofproto in order. If a flow cannot be added (e.g., the flow action is a go-to for a group id that does not exist), OvS tries to revert back all previous flows that were successfully applied from the same bundle. This is possible since OvS maintains list of old flows that were replaced by flows from the bundle. While reinserting old flows, OvS has an assertion failure due to a check on rule state != RULE_INITIALIZED. This would work for new flows, but for an old flow the rule state is RULE_REMOVED. The assertion failure causes an OvS crash.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 2.53% probability · 84th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-617
- Affected
- openvswitch/openvswitch · redhat/openstack · canonical/ubuntu linux
- Source
- cve@mitre.org
References
- https://access.redhat.com/errata/RHSA-2018:3500Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0053Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0081Third Party Advisory
- https://github.com/openvswitch/ovs/commit/0befd1f3745055c32940f5faf9559be6a14395e6Exploit, Patch, Third Party Advisory
- https://usn.ubuntu.com/3873-1/Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:3500Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0053Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0081Third Party Advisory
- https://github.com/openvswitch/ovs/commit/0befd1f3745055c32940f5faf9559be6a14395e6Exploit, Patch, Third Party Advisory
- https://usn.ubuntu.com/3873-1/Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.