Vulnerability identifier: #VU80514

Vulnerability risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-4809

CWE-ID: CWE-254

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
FreeBSD
Operating systems & Components / Operating system

Vendor: FreeBSD Foundation

Description

The vulnerability allows a remote attacker to bypass implemented firewall rules.

The vulnerability exists due to improper handling of multiple IPv6 fragment headers in pf implementation with "scrub fragment reassemble" rule. A remote attacker can send specially crafted IPv6 packets to the system and bypass implemented filtration rules.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FreeBSD: 12.0 - 13.2

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External links
http://www.freebsd.org/security/advisories/FreeBSD-SA-23:10.pf.asc

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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.