Security restrictions bypass in Linux kernel

1) Improper Initialization

EUVDB-ID: #VU55259

Risk: Low

CVSSv4.0: 0.4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-35508

CWE-ID: CWE-665 - Improper Initialization

Exploit availability: No

Description

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

The vulnerability exists due to improper initialization of the process id in the Linux kernel child/parent process identification handling while filtering signal handlers. A local user can run a specially crafted application to bypass checks to send any signal to a privileged process.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 5.12 rc1 - 5.12 rc4

CPE2.3

• cpe:2.3:o:linux_foundation:linux_kernel:5.12:rc4:*:*:*:*:*:*

External links

https://github.com/torvalds/linux/commit/b4e00444cab4c3f3fec876dc0cccc8cbb0d1a948
https://bugzilla.redhat.com/show_bug.cgi?id=1902724
https://security.netapp.com/advisory/ntap-20210513-0006/

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.