CVE-2021-33624

kernel: Linux kernel BPF protection against speculative execution attacks can be bypassed to read arbitrary kernel memory

Published Jun 23, 2021 CVSS 3.1 · 4.7 Medium EPSS < 1% KEV · Not listed
Description
In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db.

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-2021-20301 In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db.
Ubuntu USN Ubuntu USN USN-5091-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-5091-2 Linux kernel (Raspberry Pi) vulnerabilities
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-5115-1 Linux kernel (OEM) 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
May 28, 2021, 12:00 AM
Status
Modified
Published
Jun 23, 2021, 4:15 PM
Modified
Oct 8, 2026, 9:17 PM
Severity
Moderate
Public date
Jun 21, 2021, 12:00 AM