Vulnerability identifier: #VU51451

Vulnerability risk: Low

CVSSv3.1: 7.1 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:U/RC:C]

CVE-ID: CVE-2021-27365

CWE-ID: CWE-119

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 escalate privileges on the system.

The vulnerability exists due to a boundary error when processing Netlink messages in Linux kernel through 5.11.3, as certain iSCSI data structures do not have appropriate length constraints or checks, and can exceed the PAGE_SIZE value. A local unprivileged user can send a Netlink message that is associated with iSCSI, and has a length up to the maximum length of a Netlink message, trigger memory corruption and execute arbitrary code on the system with elevated privileges.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

Linux kernel:

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External links
http://bugzilla.suse.com/show_bug.cgi?id=1182715
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ec98ea7070e94cc25a422ec97d1421e28d97b7ee
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f9dbdf97a5bd92b1a49cee3d591b55b11fd7a6d5
http://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
http://www.openwall.com/lists/oss-security/2021/03/06/1

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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.