#VU55006 Use-after-free in Open vSwitch - CVE-2021-36980

Vulnerability identifier: #VU55006

Vulnerability risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-36980

CWE-ID: CWE-416

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Open vSwitch
Hardware solutions / Firmware

Vendor: openvswitch.org

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in decode_NXAST_RAW_ENCAP (called from ofpact_decode and ofpacts_decode) during the decoding of a RAW_ENCAP action. A remote attacker can send a specially crafted request to the system, trigger a use-after-free error and execute arbitrary code.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Open vSwitch: 2.11.0 - 2.15.0

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External links
http://github.com/openvswitch/ovs/commit/38744b1bcb022c611712527f039722115300f58f
http://bugs.chromium.org/p/oss-fuzz/issues/detail?id=27851
http://github.com/google/oss-fuzz-vulns/blob/main/vulns/openvswitch/OSV-2020-2197.yaml

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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.