Vulnerability identifier: #VU26235

Vulnerability risk: Low

CVSSv3.1: 3.5 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-7451

CWE-ID: CWE-401

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 gain access to sensitive kernel information.

The vulnerability exists due memory leak in IPv6 implementation in FreeBSD, when processing network traffic over TCP, which leads to disclosure of one byte of kernel memory with every TCP SYN-ACK (or challenge TCP-ACK) segment sent over IPv6. A remote attacker can initiate a TCP connection over IPv6 protocol with an affected system and gain access to sensitive information, stored in kernel.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FreeBSD: 11.0 - 12.1

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External links
http://www.freebsd.org/security/advisories/FreeBSD-SA-20:04.tcp.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.