Vulnerability identifier: #VU90051

Vulnerability risk: Low

CVSSv3.1: 7.7 [AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-47505

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 POLLFREE() function in include/uapi/asm-generic/poll.h, within the aio_poll(), aio_poll_complete_work(), aio_poll_cancel(), aio_poll_wake() and aio_poll_queue_proc() functions in fs/aio.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
http://git.kernel.org/stable/c/321fba81ec034f88aea4898993c1bf15605c023f
http://git.kernel.org/stable/c/4105e6a128e8a98455dfc9e6dbb2ab0c33c4497f
http://git.kernel.org/stable/c/47ffefd88abfffe8a040bcc1dd0554d4ea6f7689
http://git.kernel.org/stable/c/60d311f9e6381d779d7d53371f87285698ecee24
http://git.kernel.org/stable/c/50252e4b5e989ce64555c7aef7516bdefc2fea72

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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.