CVE-2018-17205: canonical ubuntu_linux Reachable Assertion

Vulnerability summary

CVE-2018-17205 is a high (CVSS 7.5) Reachable Assertion vulnerability in canonical ubuntu_linux. EPSS estimates a 2.53% chance of exploitation in the next 30 days, higher than 84.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 19-09-2018
   PublishedVulnerability first disclosed.
2. 05-08-2024
   Last modifiedVulnerability information updated.

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.

• CWE-617Reachable AssertionThe product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.