PT-2021-4234 · Linux+5 · Linux Kernel+5

Benedict Schlueter · Published 2021-07-29 · Updated 2025-01-24 · CVE-2021-34556

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Name of the Vulnerable Software and Affected Versions Linux kernel versions up to 5.13.7

Description The issue allows an unprivileged BPF program to obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack. This is possible because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack. The vulnerability can be exploited to read parts of the kernel memory.

Recommendations For Linux kernel versions up to 5.13.7, update to a version later than 5.13.7 to resolve the issue. As a temporary workaround, consider restricting the use of BPF programs to minimize the risk of exploitation.

Exploit

Fix

Side Channel Attack

Weakness Enumeration

CWE-203

Related Identifiers

ALT-PU-2021-2415

ALT-PU-2021-2486

ALT-PU-2021-2616

ALT-PU-2021-3563

ALT-PU-2021-3573

ALT-PU-2022-1240

ALT-PU-2022-1419

ALT-PU-2022-1421

ALT-PU-2023-1814

ALT-PU-2023-4894

AZL-6566

BDU:2021-04840

CVE-2021-34556

DLA-2785-1

MGASA-2021-0397

MGASA-2021-0398

OESA-2021-1324

OPENSUSE-SU-2021:1271-1

OPENSUSE-SU-2021:1477-1

OPENSUSE-SU-2021:3179-1

OPENSUSE-SU-2021:3205-1

OPENSUSE-SU-2021:3876-1

OPENSUSE-SU-2021_1271-1

OPENSUSE-SU-2021_1460-1

OPENSUSE-SU-2021_1477-1

OPENSUSE-SU-2021_3179-1

OPENSUSE-SU-2021_3205-1

OPENSUSE-SU-2021_3876-1

OPENSUSE-SU-2025_0229-1

SUSE-SU-2021:3177-1

SUSE-SU-2021:3178-1

SUSE-SU-2021:3179-1

SUSE-SU-2021:3205-1

SUSE-SU-2021:3205-2

SUSE-SU-2021:3206-1

SUSE-SU-2021:3207-1

SUSE-SU-2021:3217-1

SUSE-SU-2021:3415-1

SUSE-SU-2021:3723-1

SUSE-SU-2021:3748-1

SUSE-SU-2021:3876-1

SUSE-SU-2021:3929-1

SUSE-SU-2021:3935-1

SUSE-SU-2021:3969-1

SUSE-SU-2021:3972-1

SUSE-SU-2021_3177-1

SUSE-SU-2021_3178-1

SUSE-SU-2021_3207-1

SUSE-SU-2025:0229-1

USN-5092-1

USN-5092-2

USN-5092-3

USN-5096-1

USN-5115-1

USN-5137-1

USN-5137-2

Affected Products

Alt Linux

Astra Linux

Linuxmint

Linux Kernel

Suse

Ubuntu

References · 822

• 🔥 https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/local/cve_2022_0995_watch_queue.rb · Exploit
• 🔥 https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/local/cve_2022_1043_io_uring_priv_esc.rb · Exploit
• 🔥 https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/local/cve_2023_0386_overlayfs_priv_esc.rb · Exploit
• 🔥 https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/local/netfilter_nft_set_elem_init_privesc.rb · Exploit
• 🔥 https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/local/cve_2022_0847_dirtypipe.rb · Exploit
• 🔥 https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/local/docker_cgroup_escape.rb · Exploit
• 🔥 https://github.com/Arinerron/CVE-2022-0847-DirtyPipe-Exploit · Exploit
• 🔥 https://github.com/AlexisAhmed/CVE-2022-0847-DirtyPipe-Exploits · Exploit
• 🔥 https://github.com/tr3ee/CVE-2022-23222 · Exploit
• 🔥 https://github.com/Bonfee/CVE-2022-0995 · Exploit
• 🔥 https://github.com/Bonfee/CVE-2022-25636 · Exploit
• 🔥 https://github.com/xkaneiki/CVE-2023-0386 · Exploit
• 🔥 https://github.com/Crusaders-of-Rust/CVE-2022-0185 · Exploit
• 🔥 https://github.com/imfiver/CVE-2022-0847 · Exploit
• 🔥 https://github.com/r1is/CVE-2022-0847 · Exploit