CVE-2021-34556

kernel: BPF program can obtain sensitive information from kernel memory via a speculative store bypass side-channel attack because of the possibility of uninitialized memory locations on the BPF stack

Published Aug 2, 2021 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-2785-1 linux-4.19 security update
EUVD EUVD EUVD-2021-21206 In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack.
Ubuntu USN Ubuntu USN USN-5092-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-5092-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-5096-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-5115-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-5137-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-5137-2 Linux kernel vulnerabilities
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Oct 8, 2026, 9:03 PM
Reserved
Jun 10, 2021, 12:00 AM
Status
Modified
Published
Aug 2, 2021, 5:15 AM
Modified
Oct 8, 2026, 9:17 PM
Severity
Moderate
Public date
Aug 1, 2021, 12:00 AM