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
MediumMetricsAV: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
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