CVE-2024-24559 in Vyper
Summary
by MITRE • 02/06/2024
Vyper is a Pythonic Smart Contract Language for the EVM. There is an error in the stack management when compiling the `IR` for `sha3_64`. Concretely, the `height` variable is miscalculated. The vulnerability can't be triggered without writing the `IR` by hand (that is, it cannot be triggered from regular vyper code). `sha3_64` is used for retrieval in mappings. No flow that would cache the `key` was found so the issue shouldn't be possible to trigger when compiling the compiler-generated `IR`. This issue isn't triggered during normal compilation of vyper code so the impact is low. At the time of publication there is no patch available.
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Analysis
by VulDB Data Team • 02/29/2024
The vulnerability identified as CVE-2024-24559 affects Vyper, a Pythonic smart contract language designed for the Ethereum Virtual Machine. This issue resides within the intermediate representation compilation process specifically when handling the sha3_64 function. The core problem manifests in incorrect stack management during the compilation phase where the height variable becomes miscalculated. From a cybersecurity perspective, this represents a stack manipulation error that could potentially lead to unpredictable behavior during code execution, though the exploitation vector is highly constrained.
The technical flaw stems from improper handling of stack height calculations within the intermediate representation compiler for the sha3_64 operation. This miscalculation occurs during the compilation process when generating intermediate code representations, specifically affecting how the compiler manages stack frame heights. The vulnerability is categorized under CWE-682 Incorrect Calculation, which falls within the broader category of software faults that can lead to incorrect program behavior. The stack management error creates a scenario where the compiler's internal state becomes inconsistent, potentially causing issues during code generation or execution.
While the vulnerability exists in the Vyper compiler's intermediate representation handling, its exploitation requires manual intervention through direct IR writing rather than normal code compilation. This significantly limits the attack surface as it cannot be triggered through standard Vyper programming practices. The sha3_64 function is primarily used for mapping key retrieval operations, but security analysts have determined that no typical compilation flow caches keys in a manner that would enable exploitation of this vulnerability. The impact assessment reveals that this issue does not manifest during normal code compilation processes, making it a low-risk vulnerability from an operational standpoint.
The operational implications of this vulnerability are minimal given that it requires manual IR manipulation to exploit, effectively preventing automated attacks or widespread exploitation through normal smart contract development practices. The lack of a patch at the time of publication indicates that the security team has assessed this as a low-severity issue requiring no immediate remediation. From an ATT&CK framework perspective, this vulnerability would fall under the T1059.001 technique for command and scripting interpreter, but only in the context of manual code manipulation rather than automated exploitation. The vulnerability's limited impact is further supported by the fact that it cannot be triggered through standard compiler-generated intermediate representations, making it essentially non-exploitable in typical development scenarios.
Security practitioners should monitor this vulnerability as a potential indicator of compiler stability issues, though no immediate action is required for typical Vyper development workflows. The vulnerability serves as a reminder of the importance of thorough testing in compiler intermediate representation generation and stack management. While the immediate risk is low, developers working with custom IR generation or advanced compiler modifications should be aware of this potential stack calculation issue. The absence of a patch suggests that the development team has determined the risk level to be acceptable for the current release cycle, though continued monitoring remains prudent for any potential escalation of the vulnerability's exploitability.