#VU16579 Assertion failure in Open vSwitch - CVE-2018-17205

Vulnerability identifier: #VU16579

Vulnerability risk: Low

CVSSv4.0: 7.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2018-17205

CWE-ID: CWE-617

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Open vSwitch
Hardware solutions / Firmware

Vendor: openvswitch.org

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists in ofproto_rule_insert__ in ofproto/ofproto.c due to  flows that are added in a bundle are applied to ofproto in order during bundle commit. A remote attacker can trigger an an assertion failure due to a check on rule state != RULE_INITIALIZED while reinserting old flows and cause the service to crash.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Open vSwitch: 2.7.0 - 2.7.6

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External links
https://github.com/openvswitch/ovs/commit/0befd1f3745055c32940f5faf9559be6a14395e6

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.