#VU63577 Information disclosure in Linux kernel - CVE-2021-45486

Vulnerability identifier: #VU63577

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-45486

CWE-ID: CWE-200

Exploitation vector: Local network

Exploit availability: No

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

Vendor: Linux Foundation

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to incorrect implementation of the IPv4 protocol in the Linux kernel. A remote attacker can disclose internal state in some situations.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 5.12 rc1 - 5.12.3

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External links
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.4
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/net/ipv4/route.c?id=aa6dd211e4b1dde9d5dc25d699d35f789ae7eeba
https://arxiv.org/pdf/2112.09604.pdf

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.