#VU86247 Out-of-bounds read in Linux kernel - CVE-2021-4204

Vulnerability identifier: #VU86247

Vulnerability risk: Low

CVSSv4.0: 5.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2021-4204

CWE-ID: CWE-125

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 gain access to sensitive information.

The vulnerability exists due to a boundary condition in Linux kernel eBPF. A local user trigger an out-of-bounds read error and read contents of memory on the system or crash the kernel.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: All versions

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External links
https://access.redhat.com/security/cve/CVE-2021-4204
https://bugzilla.redhat.com/show_bug.cgi?id=2039178
https://security-tracker.debian.org/tracker/CVE-2021-4204
https://www.openwall.com/lists/oss-security/2022/01/11/4
https://security.netapp.com/advisory/ntap-20221228-0003/

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