#VU90092 Use-after-free in Linux kernel - CVE-2021-47259

Vulnerability identifier: #VU90092

Vulnerability risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-47259

CWE-ID: CWE-416

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 escalate privileges on the system.

The vulnerability exists due to a use-after-free error within the nfs4_init_client() function in fs/nfs/nfs4client.c. A local user can escalate privileges on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

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External links
https://git.kernel.org/stable/c/c7eab9e2d7b4e983ce280276fb920af649955897
https://git.kernel.org/stable/c/42c10b0db064e45f5c5ae7019bbf2168ffab766c
https://git.kernel.org/stable/c/3e3c7ebbfac152d08be75c92802a64a1f6471a15
https://git.kernel.org/stable/c/c3b6cf64dfe4ef96e7341508d50d6998da7062c7
https://git.kernel.org/stable/c/72651c6579a25317a90536181d311c663d0329ab
https://git.kernel.org/stable/c/476bdb04c501fc64bf3b8464ffddefc8dbe01577

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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.