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CVE-2018-17205

UnknownEPSS 2.53%

Last modified

CVE-2018-17205 is a vulnerability of currently unknown severity. 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. EPSS estimates a 2.53% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability
2.53%

82.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
OpenvswitchOpenvswitch>= 2.7.0, <= 2.7.6
RedhatOpenstack10
RedhatOpenstack13
CanonicalUbuntu Linux16.04
CanonicalUbuntu Linux18.04

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is 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.
How severe is CVE-2018-17205?
Severity scoring for CVE-2018-17205 is pending analysis. The EPSS model estimates a 2.53% probability of exploitation in the next 30 days.
How do I fix CVE-2018-17205?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST