GHSA-f67q-wr6w-23jq
HIGHBoa has an uncaught exception when transitioning the state of `AsyncGenerator` objects
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
boa_engineReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
A wrong assumption made when handling ECMAScript's AsyncGenerator operations can cause an uncaught exception on certain scripts.
Details
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.
Patches
Version 0.19.0 is patched to correctly handle this case.
Workarounds
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.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | boa_engine | ≥ 0.16&&< 0.19.0 | 0.19.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for boa_engine. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update boa_engine to 0.19.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f67q-wr6w-23jq is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-f67q-wr6w-23jq is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-f67q-wr6w-23jq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-f67q-wr6w-23jq in your dependencies?
O3 detects GHSA-f67q-wr6w-23jq across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.