{"cve":"CVE-2024-43367","nvd":{"published":"2024-08-15T21:15:17.777","modified":"2026-06-17T07:50:53.867","status":"Deferred","description":"Boa is an embeddable and experimental Javascript engine written in Rust. Starting in version 0.16 and prior to version 0.19.0, a wrong assumption made when handling ECMAScript's `AsyncGenerator` operations can cause an uncaught exception on certain scripts. Boa's implementation of `AsyncGenerator` makes the assumption that the state of an `AsyncGenerator` object cannot change while resolving a promise created by methods of `AsyncGenerator` such as `%AsyncGeneratorPrototype%.next`, `%AsyncGeneratorPrototype%.return`, or `%AsyncGeneratorPrototype%.throw`. However, a carefully constructed code could trigger a state transition from a getter method for the promise's `then` property, which causes the engine to fail an assertion of this assumption, causing an uncaught exception. This could be used to create a Denial Of Service attack in applications that run arbitrary ECMAScript code provided by an external user. Version 0.19.0 is patched to correctly handle this case. Users unable to upgrade to the patched version would want to use `std::panic::catch_unwind` to ensure any exceptions caused by the engine don't impact the availability of the main application.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-248"],"references":["https://github.com/boa-dev/boa/commit/69ea2f52ed976934bff588d6b566bae01be313f7","https://github.com/boa-dev/boa/security/advisories/GHSA-f67q-wr6w-23jq","https://github.com/tc39/ecma262/security/advisories/GHSA-g38c-wh3c-5h9r"],"products":[],"source":"nvd","synced_at":"2026-10-19T21:54:16.205165117+00:00"},"epss":{"cve":"CVE-2024-43367","score":0.00597,"percentile":0.48594,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-f67q-wr6w-23jq","url":"https://osv.dev/vulnerability/GHSA-f67q-wr6w-23jq","summary":"Boa has an uncaught exception when transitioning the state of `AsyncGenerator` objects","modified":"2026-09-10T03:50:17.403000789Z","packages":[{"ecosystem":"crates.io","name":"boa_engine","purl":"pkg:cargo/boa_engine","ranges":[">=0.16 <0.19.0"],"fixed":["0.19.0"]}]},{"id":"RUSTSEC-2024-0444","url":"https://osv.dev/vulnerability/RUSTSEC-2024-0444","summary":"Uncaught exception when transitioning the state of `AsyncGenerator` objects from within a property getter of `then`","modified":"2026-10-12T18:00:06.811772530Z","packages":[{"ecosystem":"crates.io","name":"boa_engine","purl":"pkg:cargo/boa_engine","ranges":[">=0.16.0 <0.19.0"],"fixed":["0.19.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}