CVE-2025-47285

Vyper is the Pythonic Programming Language for the Ethereum Virtual Machine. In versions up to and including 0.4.2rc1, `concat()` may skip evaluation of side effects when the length of an argument is zero. This is due to a fastpath in the implementation which skips evaluation of argument expressions when their length is zero. In practice, it would be very unusual in user code to construct zero-length bytestrings using an expression with side-effects, since zero-length bytestrings are typically constructed with the empty literal `b""`; the only way to construct an empty bytestring which has side effects would be with the ternary operator introduced in v0.3.8, e.g. `b"" if self.do_some_side_effect() else b""`. The fix is available in pull request 4644 and expected to be part of the 0.4.2 release. As a workaround, don't have side effects in expressions which construct zero-length bytestrings.

CVSS

No CVSS.

References

Link	Resource
https://github.com/vyperlang/vyper/blob/68b68c4b30c5ef2f312b4674676170b8a6eaa316/vyper/builtins/functions.py#L560-L562
https://github.com/vyperlang/vyper/pull/4644
https://github.com/vyperlang/vyper/security/advisories/GHSA-qhr6-mgqr-mchm

Configurations

No configuration.

History

16 May 2025, 14:43

Type	Values Removed	Values Added
New CVE

Information

Published : 2025-05-15 18:15

Updated : 2025-05-16 14:43

NVD link : CVE-2025-47285

Mitre link : CVE-2025-47285

CVE.ORG link : CVE-2025-47285

JSON object : View

Products Affected

No product.

CWE

CWE-691

Insufficient Control Flow Management

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