#VU90940 Improper error handling in Linux kernel - CVE-2021-47406

Vulnerability identifier: #VU90940

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-2021-47406

CWE-ID: CWE-388

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 improper error handling within the ext4_ext_replay_shrink_inode(), skip_hole() and ext4_ext_replay_set_iblocks() functions in fs/ext4/extents.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.10, 5.10 rc1, 5.10 rc2, 5.10 rc3, 5.10 rc4, 5.10 rc5, 5.10 rc7, 5.10.1, 5.10.2, 5.10.3, 5.10.4, 5.10.5, 5.10.6, 5.10.7, 5.10.8, 5.10.9, 5.10.10, 5.10.11, 5.10.12, 5.10.13, 5.10.14, 5.10.15, 5.10.16, 5.10.17, 5.10.18, 5.10.19, 5.10.20, 5.10.21, 5.10.22, 5.10.23, 5.10.24, 5.10.25, 5.10.26, 5.10.27, 5.10.28, 5.10.29, 5.10.30, 5.10.31, 5.10.32, 5.10.33, 5.10.34, 5.10.35, 5.10.36, 5.10.37, 5.10.38, 5.10.39, 5.10.40, 5.10.41, 5.10.42, 5.10.43, 5.10.44, 5.10.45, 5.10.46, 5.10.47, 5.10.48, 5.10.49, 5.10.50, 5.10.51, 5.10.52, 5.10.53, 5.10.54, 5.10.55, 5.10.56, 5.10.57, 5.10.58, 5.10.59, 5.10.60, 5.10.61, 5.10.62, 5.10.63, 5.10.64, 5.10.65, 5.10.66, 5.10.67, 5.10.68, 5.10.69, 5.10.70, 5.14, 5.14 rc1, 5.14 rc2, 5.14 rc3, 5.14 rc4, 5.14 rc7, 5.14.0-49.el9, 5.14.1, 5.14.2, 5.14.3, 5.14.4, 5.14.5, 5.14.6, 5.14.7, 5.14.8, 5.14.9, 5.15 rc1, 5.15 rc2, 5.15 rc3, 5.15 rc4, 5.15 rc5, 5.15 rc6, 5.15 rc7

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External links
https://git.kernel.org/stable/c/a63474dbf692dd09b50fed592bc41f6de5f102fc
https://git.kernel.org/stable/c/27e10c5d31ff1d222c7f797f1ee96d422859ba67
https://git.kernel.org/stable/c/1fd95c05d8f742abfe906620780aee4dbe1a2db0
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.71
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.14.10
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15

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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.