Improper handling of IPv6 fragment headers in FreeBSD pf



Published: 2023-09-07
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2023-4809
CWE-ID CWE-254
Exploitation vector Network
Public exploit N/A
Vulnerable software
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FreeBSD
Operating systems & Components / Operating system

Vendor FreeBSD Foundation

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Security features bypass

EUVDB-ID: #VU80514

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 - Security Features

Exploit availability: No

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

External links

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


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.



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