Kernel-memory disclosure via speculative eBPF loads
Published Mar 20, 2021 · Updated Aug 4, 2024
Information disclosure in the Linux kernel before 5.11.8 allows local users to read kernel memory through an eBPF side channel. In kernel/bpf/verifier.c, the verifier permits pointer arithmetic for types lacking ptr_limit, allowing unprivileged eBPF programs to speculatively load beyond permitted bounds. The low-privilege path requires unprivileged eBPF loading to be enabled; otherwise CAP_SYS_ADMIN or root access is required.
Summary
What happened
Information disclosure in the Linux kernel before 5.11.8 allows local users to read kernel memory through an eBPF side channel. In kernel/bpf/verifier.c, the verifier permits pointer arithmetic for types lacking ptr_limit, allowing unprivileged eBPF programs to speculatively load beyond permitted bounds. The low-privilege path requires unprivileged eBPF loading to be enabled; otherwise CAP_SYS_ADMIN or root access is required.
The record
- CVE
- CVE-2020-27170
- Published
- Mar 20, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-203, CAPEC-141, T1005
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 20, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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