Service interruption via malformed SFENCE.VMA execution
Published Jul 18, 2022 · Updated Aug 3, 2024
Improper exception handling in OpenHW Group CVA6 commit d315ddd0f1be27c1b3f27eb0b8daf471a952299a allows local users to interrupt service. The decoder in core/decoder.sv fails to require the SFENCE.VMA rd field, instruction bits 11:7, to be zero and clears the illegal-instruction state during its privilege check, so malformed encodings execute instead of trapping. Execution requires local low-privilege code on a system built with the affected processor RTL; the documented impact is availability loss, with no confidentiality or integrity impact.
Summary
What happened
Improper exception handling in OpenHW Group CVA6 commit d315ddd0f1be27c1b3f27eb0b8daf471a952299a allows local users to interrupt service. The decoder in core/decoder.sv fails to require the SFENCE.VMA rd field, instruction bits 11:7, to be zero and clears the illegal-instruction state during its privilege check, so malformed encodings execute instead of trapping. Execution requires local low-privilege code on a system built with the affected processor RTL; the documented impact is availability loss, with no confidentiality or integrity impact.
The record
- CVE
- CVE-2022-34633
- Published
- Jul 18, 2022
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-755
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Jul 18, 2022CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
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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
- Malformed SFENCE.VMA reproduction testproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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