#VU63839 Use of insufficiently random values in Linux kernel - CVE-2021-20322

Vulnerability identifier: #VU63839

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-20322

CWE-ID: CWE-330

Exploitation vector: 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 sensitive information.

The vulnerability exists due to an error when processing received ICMP errors. A remote attacker can effectively bypass the source port UDP randomization to gain access to sensitive information.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 5.15, 5.15

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External links
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/ipv4/route.c?h=v5.15-rc6&id=67d6d681e15b578c1725bad8ad079e05d1c48a8e
http://bugzilla.redhat.com/show_bug.cgi?id=2014230
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=4785305c05b25a242e5314cc821f54ade4c18810
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/ipv6/route.c?h=v5.15-rc6&id=a00df2caffed3883c341d5685f830434312e4a43
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=6457378fe796815c973f631a1904e147d6ee33b1
http://security.netapp.com/advisory/ntap-20220303-0002/
http://lists.debian.org/debian-lts-announce/2022/03/msg00012.html
http://www.debian.org/security/2022/dsa-5096

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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 Internet.

Is there known malware, which exploits this vulnerability?

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