Bug 2557978 (CVE-2020-37287)

Summary: CVE-2020-37287 vyper: vyper: Data corruption via complex type function arguments
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in vyper. An attacker interacting with an affected smart contract can cause data corruption and incorrect execution when functions process complex data types, such as multi-dimensional arrays or nested structures. The compiler incorrectly calculates the memory size of these complex argument types, leading to call stack corruption during function calls. As a result, functions receive corrupted values, which can disrupt contract logic and compromise data integrity.
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Bug Depends On: 2565614    
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Description OSIDB Bzimport 2026-10-21 00:56:31 UTC
Vyper before 0.2.6 contains a call stack corruption vulnerability that causes incorrect function outputs when complex types with non-base members are passed as arguments. Contracts passing multi-dimensional arrays or structs to internal or external functions receive corrupted values because the compiler assumed each subtype size is 32.