What is CVE-2024-43367?

CVE-2024-43367 is a high-severity security vulnerability in boa_engine (rust), affecting versions >= 0.16, < 0.19.0. It is fixed in 0.19.0.

How severe is CVE-2024-43367?

CVE-2024-43367 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of boa_engine are affected by CVE-2024-43367?

boa_engine (rust) versions >= 0.16, < 0.19.0 is affected.

Is there a fix for CVE-2024-43367?

Yes. CVE-2024-43367 is fixed in 0.19.0. Upgrade to this version or later.

Is CVE-2024-43367 exploitable, and should I be worried?

Whether CVE-2024-43367 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2024-43367 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2024-43367?

Upgrade boa_engine to 0.19.0 or later.

CVE-2024-43367 in boa_engine

Q: How severe is CVE-2024-43367?

CVE-2024-43367 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Q: Which versions of boa_engine are affected by CVE-2024-43367?

boa_engine (rust) versions >= 0.16, < 0.19.0 is affected.

Q: Is there a fix for CVE-2024-43367?

Yes. CVE-2024-43367 is fixed in 0.19.0. Upgrade to this version or later.

Q: Is CVE-2024-43367 exploitable, and should I be worried?

Whether CVE-2024-43367 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2024-43367 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2024-43367?

Upgrade boa_engine to 0.19.0 or later.

Summary

Boa has an uncaught exception when transitioning the state of AsyncGenerator objects

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.

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

Impact

CVE-2024-43367 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.19.0); upgrading removes the vulnerable code path.

Affected versions

boa_engine (>= 0.16, < 0.19.0)

Security releases

boa_engine → 0.19.0 (rust)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

Version 0.19.0 is patched to correctly handle this case.

Frequently Asked Questions

What is CVE-2024-43367? CVE-2024-43367 is a high-severity security vulnerability in boa_engine (rust), affecting versions >= 0.16, < 0.19.0. It is fixed in 0.19.0.
How severe is CVE-2024-43367? CVE-2024-43367 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
Which versions of boa_engine are affected by CVE-2024-43367? boa_engine (rust) versions >= 0.16, < 0.19.0 is affected.
Is there a fix for CVE-2024-43367? Yes. CVE-2024-43367 is fixed in 0.19.0. Upgrade to this version or later.
Is CVE-2024-43367 exploitable, and should I be worried? Whether CVE-2024-43367 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2024-43367 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2024-43367? Upgrade boa_engine to 0.19.0 or later.