Cross-instance data disclosure via stale heap mapping
Published Nov 10, 2022 · Updated May 2, 2025
Information disclosure in Bytecode Alliance Wasmtime before 1.0.2 and 2.0.0 through 2.0.1 allows remote attackers to read prior heap images. The pooling allocator leaves a prior module's copy-on-write image mapped when it reuses the slot for a module without a heap image. Exploitation requires the nondefault pooling allocator, enabled copy-on-write initialization, and a crafted guest module; later reuse can segfault the host.
Summary
What happened
Information disclosure in Bytecode Alliance Wasmtime before 1.0.2 and 2.0.0 through 2.0.1 allows remote attackers to read prior heap images. The pooling allocator leaves a prior module's copy-on-write image mapped when it reuses the slot for a module without a heap image. Exploitation requires the nondefault pooling allocator, enabled copy-on-write initialization, and a crafted guest module; later reuse can segfault the host.
The record
- CVE
- CVE-2022-39393
- Published
- Nov 10, 2022
- Updated
- May 2, 2025
- Vendor
- Bytecode Alliance
- Product
- Wasmtime
- Classifications
- CWE-226, T1005
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 10, 2022CVE publishedPublication date reported by the CVE source.
- May 2, 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=< 1.0.2
- Affected versionversion=>= 2.0.0, < 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
- switch_image_and_non_image regression testproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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