Guest-to-host memory access via miscompiled shifted addresses
Published Mar 8, 2023 · Updated Feb 25, 2025
Out-of-bounds access in Cranelift in Bytecode Alliance Wasmtime allows attackers to read or write host memory via malicious WebAssembly. The x86_64 backend folds a zero-extended, shifted 32-bit WebAssembly address into a 64-bit addressing mode without required 32-bit truncation. Default code generation on x86_64 lets a malicious guest access memory roughly 6 GB to 34 GB beyond linear memory, including other instances or embedder memory.
Summary
What happened
Out-of-bounds access in Cranelift in Bytecode Alliance Wasmtime allows attackers to read or write host memory via malicious WebAssembly. The x86_64 backend folds a zero-extended, shifted 32-bit WebAssembly address into a 64-bit addressing mode without required 32-bit truncation. Default code generation on x86_64 lets a malicious guest access memory roughly 6 GB to 34 GB beyond linear memory, including other instances or embedder memory.
The record
- CVE
- CVE-2023-26489
- Published
- Mar 8, 2023
- Updated
- Feb 25, 2025
- Vendor
- Bytecode Alliance
- Product
- Wasmtime
- Classifications
- CWE-125, CWE-787
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 8, 2023CVE publishedPublication date reported by the CVE source.
- Feb 25, 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=cranelift-codegen: >= 0.84.0, < 0.91.1
- Affected versionversion=cranelift-codegen: >= 0.92.0, < 0.92.1
- Affected versionversion=cranelift-codegen: >= 0.93.0, < 0.93.1
- Affected versionversion=wasmtime: >= 0.37.0, < 4.0.1
- Affected versionversion=wasmtime: >= 5.0.0, < 5.0.1
- Affected versionversion=wasmtime: >= 6.0.0, < 6.0.1
What conditions does exploitation require?
What is affected?
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.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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