Vulnerability identifier: #VU66477

Vulnerability risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-35039

CWE-ID: CWE-347

Exploitation vector: Local

Exploit availability: No

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

Vendor:

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to improper signature handling in the kernel/module.c in Linux kernel. If the kernel module is not signed, it still can be loaded into the system via init_module if module.sig_enforce=1 command-line argument is used. As a result, a local user can load unsigned and potentially malicious kernel modules.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

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External links
http://www.openwall.com/lists/oss-security/2021/07/06/3
http://github.com/torvalds/linux/commit/0c18f29aae7ce3dadd26d8ee3505d07cc982df75
http://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.14
http://www.openwall.com/lists/oss-security/2021/07/06/3
http://security.netapp.com/advisory/ntap-20210813-0004/
http://lists.debian.org/debian-lts-announce/2021/10/msg00010.html
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0c18f29aae7ce3dadd26d8ee3505d07cc982df75

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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.