#VU90246 Use-after-free in Linux kernel - CVE-2021-46959

Vulnerability identifier: #VU90246

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-2021-46959

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 devm_spi_alloc_master(), devm_spi_register_master() and spi_unregister_master() functions in drivers/spi/spi.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/62bb2c7f2411a0045c24831f11ecacfc35610815
https://git.kernel.org/stable/c/8bf96425c90f5c1dcf3b7b9df568019a1d4b8a0e
https://git.kernel.org/stable/c/8e029707f50a82c53172359c686b2536ab54e58c
https://git.kernel.org/stable/c/28a5529068c51cdf0295ab1e11a99a3a909a03e4
https://git.kernel.org/stable/c/001c8e83646ad3b847b18f6ac55a54367d917d74
https://git.kernel.org/stable/c/c7fabe372a9031acd00498bc718ce27c253abfd1
https://git.kernel.org/stable/c/cee78aa24578edac8cf00513dca618c0acc17cd7
https://git.kernel.org/stable/c/8735248ebb918d25427965f0db07939ed0473ec6
https://git.kernel.org/stable/c/794aaf01444d4e765e2b067cba01cc69c1c68ed9

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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.