#VU60356 Heap-based buffer overflow in Linux kernel - CVE-2021-20194

Vulnerability identifier: #VU60356

Vulnerability risk: Low

CVSSv4.0: 4.4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-20194

CWE-ID: CWE-122

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 within the __cgroup_bpf_run_filter_getsockopt() function, when kernel is compiled with config params CONFIG_BPF_SYSCALL=y , CONFIG_BPF=y , CONFIG_CGROUPS=y , CONFIG_CGROUP_BPF=y , CONFIG_HARDENED_USERCOPY not set, and BPF hook to getsockopt is registered. A local user can trigger a heap-based buffer overflow and execute arbitrary code with elevated privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 5.2

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1912683
https://security.netapp.com/advisory/ntap-20210326-0003/

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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.