Kernel-memory disclosure via unprotected BPF stack stores
Published Aug 2, 2021 · Updated Aug 4, 2024
Information disclosure in the Linux kernel through 5.13.7 allows local users to read arbitrary kernel memory through a BPF side channel. The BPF verifier leaves the first store to each uninitialized stack slot unprotected, allowing a dependent load to speculatively consume unsanitized prior contents. Exploitation requires the ability to run an unprivileged BPF program on susceptible hardware; the demonstrated consequence is arbitrary kernel-memory disclosure.
Summary
What happened
Information disclosure in the Linux kernel through 5.13.7 allows local users to read arbitrary kernel memory through a BPF side channel. The BPF verifier leaves the first store to each uninitialized stack slot unprotected, allowing a dependent load to speculatively consume unsanitized prior contents. Exploitation requires the ability to run an unprivileged BPF program on susceptible hardware; the demonstrated consequence is arbitrary kernel-memory disclosure.
The record
- CVE
- CVE-2021-34556
- Published
- Aug 2, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-203
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 2, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
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Your stack
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