Host filesystem access via implicit working-directory mapping
Published Dec 22, 2023 · Updated Apr 17, 2025
Improper access control in Wasmer 3.0.0 through 4.2.3 allows local users to read or write host files through untrusted Wasm code. The CLI opens its current working directory to a WASI module by default, even when no --dir mapping authorizes host filesystem access. Exploitation requires executing attacker-controlled Wasm locally or through a service, with file access limited by the Wasmer process's host permissions.
Summary
What happened
Improper access control in Wasmer 3.0.0 through 4.2.3 allows local users to read or write host files through untrusted Wasm code. The CLI opens its current working directory to a WASI module by default, even when no --dir mapping authorizes host filesystem access. Exploitation requires executing attacker-controlled Wasm locally or through a service, with file access limited by the Wasmer process's host permissions.
The record
- CVE
- CVE-2023-51661
- Published
- Dec 22, 2023
- Updated
- Apr 17, 2025
- Vendor
- Wasmer
- Product
- Wasmer
- Classifications
- CWE-284, T1611
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 22, 2023CVE publishedPublication date reported by the CVE source.
- Apr 17, 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=>= 3.0.0, < 4.2.4
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.
Public exploit references
- WASI working-directory file-creation proof of conceptproof of concept · demonstrated
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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