#VU77624 Out-of-bounds read in Linux kernel - CVE-2023-34256

Vulnerability identifier: #VU77624

Vulnerability risk: Low

CVSSv4.0: 1.9 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2023-34256

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 perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary condition within crc16 in lib/crc16.c when called from fs/ext4/super.c. A local user can trigger an out-of-bounds read error and crash the kernel.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 6.3.3, 6.3.3

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External links
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4f04351888a83e595571de672e0a4a8b74f4fb31
https://syzkaller.appspot.com/bug?extid=8785e41224a3afd04321
https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.3.3
https://bugzilla.suse.com/show_bug.cgi?id=1211895

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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.