#VU51545 Buffer overflow in Linux kernel - CVE-2020-25211

Vulnerability identifier: #VU51545

Vulnerability risk: Low

CVSSv4.0: 4.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-25211

CWE-ID: CWE-119

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local user to crash the system.

The vulnerability exists due to a boundary error within the ctnetlink_parse_tuple_filter() function in net/netfilter/nf_conntrack_netlink.c. A local user can inject conntrack netlink configuration, trigger buffer overflow and crash the kernel or force usage of incorrect protocol numbers.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 5.8.8, 5.8.8

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External links
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1cc5ef91d2ff94d2bf2de3b3585423e8a1051cb6
https://lists.debian.org/debian-lts-announce/2020/10/msg00028.html
https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html
https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BL2O4JAMPJG4YMLLJ7JFDHDJRXN4RKTC/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OLDYVOM4OS55HA45Y3UEVLDHYGFXPZUX/
https://security.netapp.com/advisory/ntap-20201009-0001/
https://twitter.com/grsecurity/status/1303646421158109185
https://www.debian.org/security/2020/dsa-4774

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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.