Contract reentrancy via empty lock key
Published Sep 18, 2023 · Updated Sep 24, 2024
Improper locking in Vyper 0.2.9 through 0.3.9 allows attackers to deploy contracts whose empty-key nonreentrant functions permit reentry. The compiler's function-decorator parser accepts an empty string as the nonreentrant key, but code generation emits no runtime lock for that falsy value. Exploitation requires a contract compiled with the empty-key decorator and a callable path that reenters it, permitting unintended state changes.
Summary
What happened
Improper locking in Vyper 0.2.9 through 0.3.9 allows attackers to deploy contracts whose empty-key nonreentrant functions permit reentry. The compiler's function-decorator parser accepts an empty string as the nonreentrant key, but code generation emits no runtime lock for that falsy value. Exploitation requires a contract compiled with the empty-key decorator and a callable path that reenters it, permitting unintended state changes.
The record
- CVE
- CVE-2023-42441
- Published
- Sep 18, 2023
- Updated
- Sep 24, 2024
- Vendor
- Vyper
- Product
- Vyper
- Classifications
- CWE-667, CWE-833
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 18, 2023CVE publishedPublication date reported by the CVE source.
- Sep 24, 2024Record 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=>= 0.2.9, < 0.3.10
- Affected versionversion=0.2.9 <0.3.10
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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