#VU26466 Buffer overflow in Linux kernel


Published: 2020-06-03 | Updated: 2023-03-24

Vulnerability identifier: #VU26466

Vulnerability risk: Low

CVSSv3.1: 7.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-8835

CWE-ID: CWE-119

Exploitation vector: Local

Exploit availability: Yes

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 in bpf verifier for 32 bit systems in Linux kernel. A local user can rigger a buffer overflow and gain access to sensitive information or execute arbitrary code on the system with elevated privileges.

Mitigation

Install updates from vendor's website.

As a temporary solution set the following sysctl:

kernel.unprivileged_bpf_disabled = 1

Vulnerable software versions

Linux kernel: 5.5 - 5.5.13


External links
http://lore.kernel.org/bpf/20200330160324.15259-1-daniel
http://seclists.org/oss-sec/2020/q1/127


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. However, proof of concept for this vulnerability is available.


Latest bulletins with this vulnerability