Vulnerability identifier: #VU63667

Vulnerability risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-40490

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 user to escalate privileges on the system.

The vulnerability exists due to a race condition in ext4_write_inline_data_end in fs/ext4/inline.c in the ext4 subsystem in the Linux kernel. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel:

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External links
http://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git/commit/?id=9e445093e523f3277081314c864f708fd4bd34aa
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XJGX3DMJT6MRBW2XEF3TWVHYWZW3DG3N/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/M6VS2DLGT7TK7URKAS2KWJL3S533SGVA/
http://www.debian.org/security/2021/dsa-4978
http://security.netapp.com/advisory/ntap-20211004-0001/
http://lists.debian.org/debian-lts-announce/2021/10/msg00010.html
http://lists.debian.org/debian-lts-announce/2021/12/msg00012.html

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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.