#VU75454 Security features bypass in Linux kernel - CVE-2023-1998

Vulnerability identifier: #VU75454

Vulnerability risk: Low

CVSSv4.0: 5.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2023-1998

CWE-ID: CWE-254

Exploitation vector: Local

Exploit availability: Yes

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

Vendor: Linux Foundation

Description

The vulnerability allows a local user to bypass implemented security restrictions.

The vulnerability exists due to incorrect implementation of the Spectre v2 SMT mitigations, related to calling prctl with PR_SET_SPECULATION_CTRL. An attacker can gain unauthorized access to kernel memory from userspace.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 6.3, 6.3

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External links
https://kernel.dance/#6921ed9049bc7457f66c1596c5b78aec0dae4a9d
https://github.com/google/security-research/security/advisories/GHSA-mj4w-6495-6crx
https://github.com/torvalds/linux/commit/6921ed9049bc7457f66c1596c5b78aec0dae4a9d

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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. However, proof of concept for this vulnerability is available.