Contract-call reversion via unsigned comparison of signed start
Published Apr 25, 2024 · Updated Aug 2, 2024
Incorrect code generation in Vyper 0.3.8 through 0.3.10 allows remote attackers to force affected smart-contract calls to revert. stmt.parse_For_range() emits an unsigned le assertion for a signed start value, so a negative value is interpreted as a very large integer and the assertion fails. The contract must contain range(start, start + N) with a signed start that a caller can make negative, preventing that invocation from completing.
Summary
What happened
Incorrect code generation in Vyper 0.3.8 through 0.3.10 allows remote attackers to force affected smart-contract calls to revert. stmt.parse_For_range() emits an unsigned le assertion for a signed start value, so a negative value is interpreted as a very large integer and the assertion fails. The contract must contain range(start, start + N) with a signed start that a caller can make negative, preventing that invocation from completing.
The record
- CVE
- CVE-2024-32481
- Published
- Apr 25, 2024
- Updated
- Aug 2, 2024
- Vendor
- Vyper
- Product
- Vyper
- Classifications
- CWE-681
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 25, 2024CVE publishedPublication date reported by the CVE source.
- Aug 2, 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=>= 0.3.8, < 0.4.0b1
- Affected versionversion=0.3.8 <=0.4.0b1
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
- Upstream negative signed-range proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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