#VU91489 Race condition in Linux kernel - CVE-2021-20261

Vulnerability identifier: #VU91489

Vulnerability risk: Low

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-20261

CWE-ID: CWE-362

Exploitation vector: Local

Exploit availability: No

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

Vendor: Linux Foundation

Description

The vulnerability allows a local privileged user to execute arbitrary code.

The vulnerability exists due to a race condition within the set_fdc(), do_format(), user_reset_fdc(), set_geometry(), get_floppy_geometry(), fd_locked_ioctl(), floppy_check_events() and floppy_revalidate() functions in drivers/block/floppy.c. A local privileged user can execute arbitrary code.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1932150
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a0c80efe5956ccce9fe7ae5c78542578c07bc20a

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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.