{"id":63032,"date":"2025-05-15T22:32:12","date_gmt":"2025-05-15T19:02:12","guid":{"rendered":"https:\/\/afaghhosting.net\/blog\/cve-2025-47774-vyper-uninitialized-side-effect-elision-in-slice-builtin\/"},"modified":"2025-05-15T22:32:12","modified_gmt":"2025-05-15T19:02:12","slug":"cve-2025-47774-vyper-uninitialized-side-effect-elision-in-slice-builtin","status":"publish","type":"post","link":"https:\/\/afaghhosting.net\/blog\/cve-2025-47774-vyper-uninitialized-side-effect-elision-in-slice-builtin\/","title":{"rendered":"CVE-2025-47774 &#8211; Vyper Uninitialized Side Effect Elision in Slice Builtin"},"content":{"rendered":"<p><strong>CVE ID : <\/strong>CVE-2025-47774<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, the `slice()` builtin can elide side effects when the output length is 0, and the source bytestring is a builtin (`msg.data` or `<\/p>\n<address>.code`). The reason is that for these source locations, the check that `length &gt;= 1` is skipped. The result is that a 0-length bytestring constructed with slice can be passed to `make_byte_array_copier`, which elides evaluation of its source argument when the max length is 0. The impact is that side effects in the `start` argument may be elided when the `length` argument is 0, e.g. `slice(msg.data, self.do_side_effect(), 0)`. The fix in pull request 4645 disallows any invocation of `slice()` with length 0, including for the ad hoc locations discussed in this advisory. The fix is expected to be part of version 0.4.2.<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;<\/address>\n","protected":false},"excerpt":{"rendered":"<p>CVE ID : CVE-2025-47774 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, the `slice()` builtin can elide side effects when the output length is 0, and the source bytestring is a builtin (`msg.data` &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-63032","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/63032","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=63032"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/63032\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=63032"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=63032"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=63032"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}