#VU36608 NULL pointer dereference in FreeBSD - CVE-2018-6925

Vulnerability identifier: #VU36608

Vulnerability risk: Medium

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2018-6925

CWE-ID: CWE-476

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
FreeBSD
Operating systems & Components / Operating system

Vendor: FreeBSD Foundation

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in FreeBSD before 11.2-STABLE(r338986), 11.2-RELEASE-p4, 11.1-RELEASE-p15, 10.4-STABLE(r338985), and 10.4-RELEASE-p13, due to improper maintenance of IPv6 protocol control block flags through various failure paths, an unprivileged authenticated local user may be able to cause a NULL pointer dereference causing the kernel to crash. A remote attacker can perform a denial of service (DoS) attack.

Mitigation
Update to version 11.2.

Vulnerable software versions

FreeBSD: 11.0 - 11.1

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External links
http://security.FreeBSD.org/advisories/FreeBSD-EN-18:11.listen.asc
http://www.flexera.com/company/secunia-research/advisories/SR-2018-21.html

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.