{"uuid": "9fca3700-59a9-4444-bab5-5ef696ea7ab4", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2025-47285", "type": "published-proof-of-concept", "source": "https://t.me/DarkWebInformer_CVEAlerts/16541", "content": "\ud83d\udd17 DarkWebInformer.com - Cyber Threat Intelligence\n\ud83d\udccc CVE ID: CVE-2025-47285\n\ud83d\udd25 CVSS Score: 2.9 (cvssV4_0, Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P)\n\ud83d\udd39 Description: 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.\n\ud83d\udccf Published: 2025-05-15T17:24:03.442Z\n\ud83d\udccf Modified: 2025-05-15T17:24:03.442Z\n\ud83d\udd17 References:\n1. https://github.com/vyperlang/vyper/security/advisories/GHSA-qhr6-mgqr-mchm\n2. https://github.com/vyperlang/vyper/pull/4644\n3. https://github.com/vyperlang/vyper/blob/68b68c4b30c5ef2f312b4674676170b8a6eaa316/vyper/builtins/functions.py#L560-L562", "creation_timestamp": "2025-05-15T17:34:32.000000Z"}