Vulnerability identifier: #VU51543

Vulnerability risk: Low

CVSSv3.1:

CVE-ID: CVE-2020-29661

CWE-ID: CWE-667

Exploitation vector: Local

Exploit availability: No

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

Vendor:

Description

The vulnerability allows a local user to perform a escalate privileges on the system.

The vulnerability exists due to locking error in the tty subsystem of the Linux kernel in drivers/tty/tty_jobctrl.c. An local user can exploit this vulnerability to trigger a use-after-free error against TIOCSPGRP and execute arbitrary code with elevated privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

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External links
http://packetstormsecurity.com/files/160681/Linux-TIOCSPGRP-Broken-Locking.html
http://www.openwall.com/lists/oss-security/2020/12/10/1
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=54ffccbf053b5b6ca4f6e45094b942fab92a25fc
http://lists.debian.org/debian-lts-announce/2021/02/msg00018.html
http://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BOB25SU6XUL4TNP7KB63WNZSYTIYFDPP/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MZ7OAKAEFAXQRGBZK4LYUWINCD3D2XCL/
http://security.netapp.com/advisory/ntap-20210122-0001/
http://www.debian.org/security/2021/dsa-4843

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Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?