PT-2021-4234

CVE-2021-34556

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Published

2021-07-29

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Updated

2025-07-26

Description by

CVSS 3.1
5.5
Medium
MetricsAV: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.
Exploitability
Exploit
Fix
Impacts
Researchers
Vendors
Affected products
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
DLA-2785-1
MGASA-2021-0397
MGASA-2021-0398
OESA-2021-1324
OPENSUSE-SU-2021:1271-1
OPENSUSE-SU-2021_1271-1
OPENSUSE-SU-2021_1460-1
OPENSUSE-SU-2021:1477-1
OPENSUSE-SU-2021_1477-1
OPENSUSE-SU-2021:3179-1
OPENSUSE-SU-2021_3179-1
OPENSUSE-SU-2021:3205-1
OPENSUSE-SU-2021_3205-1
OPENSUSE-SU-2021:3876-1
OPENSUSE-SU-2021_3876-1
OPENSUSE-SU-2025_0229-1
SUSE-SU-2021:3177-1
SUSE-SU-2021_3177-1
SUSE-SU-2021:3178-1
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_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-2025:0229-1
USN-5092-1
USN-5092-2
USN-5092-3
USN-5096-1
USN-5115-1
USN-5137-1
USN-5137-2
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