Kernel memory disclosure via return-stack-buffer underflow
Published Jul 12, 2022 · Updated Aug 3, 2024
Information disclosure in Intel microprocessor generations 6 through 8 allows local users to read kernel data through speculative execution. When the return stack buffer underflows, affected processors use alternate branch predictors for kernel RET instructions, allowing user-mode code to select a transient target despite retpoline. Unprivileged local access, a susceptible microarchitecture, and suitable disclosure gadgets are required; the demonstrated Linux attack extracts kernel memory.
Summary
What happened
Information disclosure in Intel microprocessor generations 6 through 8 allows local users to read kernel data through speculative execution. When the return stack buffer underflows, affected processors use alternate branch predictors for kernel RET instructions, allowing user-mode code to select a transient target despite retpoline. Unprivileged local access, a susceptible microarchitecture, and suitable disclosure gadgets are required; the demonstrated Linux attack extracts kernel memory.
The record
- CVE
- CVE-2022-29901
- Published
- Jul 12, 2022
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-200, CWE-668, T1003.008
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 12, 2022CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- RETBleed Artifactfunctional · demonstrated
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Technologies
Your stack
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Your stack
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