Vulnerability in Openvswitch
CVE-2018-17205
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.025 (84.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 84.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.025 · newest: 0.025 · change: 0.000
Affected products
- Openvswitch
- Canonical Ubuntu Linux — versions 16.04, 18.04
- Red Hat OpenStack — versions 10, 13
Weakness classification (CWE)
References
- access.redhat.com/errata/RHSA-2019:0053 (vendor-advisory, Third Party Advisory)
- usn.ubuntu.com/3873-1/ (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2018:3500 (vendor-advisory, Third Party Advisory)
- github.com/openvswitch/ovs/commit/0befd1f3745055c32940f5faf9559be6a14395e6 (Exploit, Patch, Third Party Advisory)
- access.redhat.com/errata/RHSA-2019:0081 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2018-17205?
- CVE-2018-17205 is a high-severity vulnerability in Openvswitch, classified under Reachable Assertion. CVSS score: 7.5/10. Published 2018-09-19.
- How severe is CVE-2018-17205?
- High severity. CVSS v3 base score is 7.5 out of 10.