CVE-2018-17205 Information

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 Vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Reference

https://access.redhat.com/errata/RHSA-2018:3500 https://access.redhat.com/errata/RHSA-2019:0053 https://access.redhat.com/errata/RHSA-2019:0081 https://github.com/openvswitch/ovs/commit/0befd1f3745055c32940f5faf9559be6a14395e6 https://usn.ubuntu.com/3873-1/

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

7.5