#VU93740 Improper privilege management in Linux kernel - CVE-2021-46918

Vulnerability identifier: #VU93740

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-2021-46918

CWE-ID: CWE-269

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.

The vulnerability exists due to improperly imposed permissions within the idxd_setup_interrupts() and idxd_shutdown() functions in drivers/dma/idxd/init.c, within the idxd_device_drain_pasid() function in drivers/dma/idxd/device.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.11, 5.11 rc1, 5.11.1, 5.11.2, 5.11.3, 5.11.4, 5.11.5, 5.11.6, 5.11.7, 5.11.8, 5.11.9, 5.11.10, 5.11.11, 5.11.12, 5.11.13, 5.11.14, 5.11.15, 5.12 rc1, 5.12 rc2, 5.12 rc3, 5.12 rc4, 5.12 rc6, 5.12 rc8

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External links
https://git.kernel.org/stable/c/c84b8982d7aa9b4717dc36a1c6cbc93ee153b500
https://git.kernel.org/stable/c/6df0e6c57dfc064af330071f372f11aa8c584997
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.16
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12

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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.