#VU63578 Out-of-bounds read in Linux kernel - CVE-2021-45469

Vulnerability identifier: #VU63578

Vulnerability risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-45469

CWE-ID: CWE-125

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 execute arbitrary code.

The vulnerability exists due to a boundary condition in the __f2fs_setxattr() function in fs/f2fs/xattr.c in the Linux kernel when an inode has an invalid last xattr entry. A local user can create a specially crafted f2fs image, trigger an out-of-bounds read error, and perform a denial of service attack or possibly execute arbitrary code.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 5.15 rc1 - 5.15.25

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External links
https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git/commit/?h=dev&id=5598b24efaf4892741c798b425d543e4bed357a1
https://bugzilla.kernel.org/show_bug.cgi?id=215235
https://www.openwall.com/lists/oss-security/2021/12/25/1
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/AK2C4A43BZSWATZWFUHHHUQF3HPIALNP/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QG7XV2WXKMSMKIQKIBG5LW3Y3GXEWG5Q/
https://security.netapp.com/advisory/ntap-20220114-0003/
https://www.debian.org/security/2022/dsa-5050
https://www.debian.org/security/2022/dsa-5096
https://lists.debian.org/debian-lts-announce/2022/03/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.