#VU90669 NULL pointer dereference in Linux kernel - CVE-2020-25285

Vulnerability identifier: #VU90669

Vulnerability risk: Low

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-25285

CWE-ID: CWE-476

Exploitation vector: Local

Exploit availability: No

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

Vendor: Linux Foundation

Description

The vulnerability allows a local privileged user to execute arbitrary code.

The vulnerability exists due to NULL pointer dereference within the allowed_mems_nr(), hugetlb_sysctl_handler_common() and hugetlb_overcommit_handler() functions in mm/hugetlb.c. A local privileged user can execute arbitrary code.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.8 rc1 - 5.8.7

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External links
https://twitter.com/grsecurity/status/1303749848898904067
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=17743798d81238ab13050e8e2833699b54e15467
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8.8
https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html
https://security.netapp.com/advisory/ntap-20201009-0002/
https://usn.ubuntu.com/4576-1/
https://usn.ubuntu.com/4579-1/
https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html
https://lists.debian.org/debian-lts-announce/2020/10/msg00032.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.