Host-memory read and write via zero-page mapping
Published Nov 10, 2022 · Updated Apr 23, 2025
Out-of-bounds memory access in Bytecode Alliance Wasmtime before 2.0.2 allows attackers to read and write host memory via guest loads and stores. The pooling instance allocator reserves a zero-byte mapping when InstanceLimits::memory_pages is zero, defeating page-fault bounds enforcement. Exploitation requires an embedding to enable the nondefault pooling allocator and set memory_pages to zero; access is limited to host memory within range of the pool mapping.
Summary
What happened
Out-of-bounds memory access in Bytecode Alliance Wasmtime before 2.0.2 allows attackers to read and write host memory via guest loads and stores. The pooling instance allocator reserves a zero-byte mapping when InstanceLimits::memory_pages is zero, defeating page-fault bounds enforcement. Exploitation requires an embedding to enable the nondefault pooling allocator and set memory_pages to zero; access is limited to host memory within range of the pool mapping.
The record
- CVE
- CVE-2022-39392
- Published
- Nov 10, 2022
- Updated
- Apr 23, 2025
- Vendor
- Bytecode Alliance
- Product
- Wasmtime
- Classifications
- CWE-119, CWE-787, CWE-125, T1068
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 10, 2022CVE publishedPublication date reported by the CVE source.
- Apr 23, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.0.2
What conditions does exploitation require?
What is affected?
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
- zero_memory_pages_disallows_oob regression testproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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