{"id":63033,"date":"2025-05-15T22:32:16","date_gmt":"2025-05-15T19:02:16","guid":{"rendered":"https:\/\/afaghhosting.net\/blog\/cve-2025-47285-vyper-ethereum-virtual-machine-side-effect-evaluation-vulnerability\/"},"modified":"2025-05-15T22:32:16","modified_gmt":"2025-05-15T19:02:16","slug":"cve-2025-47285-vyper-ethereum-virtual-machine-side-effect-evaluation-vulnerability","status":"publish","type":"post","link":"https:\/\/afaghhosting.net\/blog\/cve-2025-47285-vyper-ethereum-virtual-machine-side-effect-evaluation-vulnerability\/","title":{"rendered":"CVE-2025-47285 &#8211; Vyper Ethereum Virtual Machine Side-Effect Evaluation Vulnerability"},"content":{"rendered":"<p><strong>CVE ID : <\/strong>CVE-2025-47285<br \/>\n<br \/>\n<strong>Published : <\/strong> May 15, 2025, 6:15 p.m. | 43\u00a0minutes ago<br \/>\n<br \/>\n<strong>Description : <\/strong>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&#8221;&#8221;`; 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&#8221;&#8221; if self.do_some_side_effect() else b&#8221;&#8221;`. The fix is available in pull request 4644 and expected to be part of the 0.4.2 release. As a workaround, don&#8217;t have side effects in expressions which construct zero-length bytestrings.<br \/>\n<br \/>\n<strong>Severity:<\/strong> 0.0 | NA<br \/>\n<br \/>\nVisit the link for more details, such as CVSS details, affected products, timeline, and more&#8230;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>CVE ID : CVE-2025-47285 Published : May 15, 2025, 6:15 p.m. | 43\u00a0minutes ago 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 &hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"class_list":["post-63033","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/63033","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/comments?post=63033"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/63033\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=63033"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=63033"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=63033"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}