#VU95192 Null pointer dereference in Linux kernel - CVE-2020-27830

Vulnerability identifier: #VU95192

Vulnerability risk: Low

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:Clear]

CVE-ID: CVE-2020-27830

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 user to perform a denial of service (DoS) attack.

A vulnerability was found in Linux Kernel where in the spk_ttyio_receive_buf2() function, it would dereference spk_ttyio_synth without checking whether it is NULL or not, and may lead to a NULL-ptr deref crash.

Mitigation
Install update from vendor's repository.

Vulnerable software versions

Linux kernel: All versions

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1919900
https://www.openwall.com/lists/oss-security/2020/12/08/1
https://www.openwall.com/lists/oss-security/2020/12/08/4
https://www.debian.org/security/2021/dsa-4843
https://lists.debian.org/debian-lts-announce/2021/02/msg00018.html
https://security.netapp.com/advisory/ntap-20210625-0004/

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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.