#VU46226 Heap-based buffer overflow in FreeBSD - CVE-2020-7461

Vulnerability identifier: #VU46226

Vulnerability risk: Medium

CVSSv4.0: 7.4 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2020-7461

CWE-ID: CWE-122

Exploitation vector: Local network

Exploit availability: Yes

Vulnerable software:
FreeBSD
Operating systems & Components / Operating system

Vendor: FreeBSD Foundation

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when parsing option 119 data in DHCP packets in dhclient(8). A remote attacker on the local network can send specially crafted data to the DHCP client, trigger heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FreeBSD: 11.0 - 12.1

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External links
https://www.freebsd.org/security/advisories/FreeBSD-SA-20:26.dhclient.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 local network (LAN).

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.