What is CVE-2020-36442?

CVE-2020-36442 is a high-severity race condition vulnerability in beef (rust), affecting versions < 0.5.0. It is fixed in 0.5.0. Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing.

How severe is CVE-2020-36442?

CVE-2020-36442 has a CVSS score of 8.1 (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 beef are affected by CVE-2020-36442?

beef (rust) versions < 0.5.0 is affected.

Is there a fix for CVE-2020-36442?

Yes. CVE-2020-36442 is fixed in 0.5.0. Upgrade to this version or later.

Is CVE-2020-36442 exploitable, and should I be worried?

Whether CVE-2020-36442 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-2020-36442 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.

CVE-2020-36442 in beef

Q: How severe is CVE-2020-36442?

CVE-2020-36442 has a CVSS score of 8.1 (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 beef are affected by CVE-2020-36442?

beef (rust) versions < 0.5.0 is affected.

Q: Is there a fix for CVE-2020-36442?

Yes. CVE-2020-36442 is fixed in 0.5.0. Upgrade to this version or later.

Q: Is CVE-2020-36442 exploitable, and should I be worried?

Whether CVE-2020-36442 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-2020-36442 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-2020-36442?

Upgrade beef to 0.5.0 or later.

Summary

Data races in beef

An issue was discovered in the beef crate before 0.5.0 for Rust.
Affected versions of this crate did not have a T: Sync bound in the Send impl for Cow<'_, T, U>. This allows users to create data races by making Cow contain types that are (Send && !Sync) like Cell<_> or RefCell<_>.

Such data races can lead to memory corruption.

The flaw was corrected in commit d1c7658 by adding trait bounds T: Sync and T::Owned: Send to the Send impl for Cow<'_, T, U>.

Impact

Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing. Typical impact: TOCTOU exploits, data corruption, or privilege escalation.

CVE-2020-36442 has a CVSS score of 8.1 (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 (0.5.0); upgrading removes the vulnerable code path.

Affected versions

beef (< 0.5.0)

Security releases

beef → 0.5.0 (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

Upgrade beef to 0.5.0 or later to resolve this vulnerability.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is CVE-2020-36442? CVE-2020-36442 is a high-severity race condition vulnerability in beef (rust), affecting versions < 0.5.0. It is fixed in 0.5.0. Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing.
How severe is CVE-2020-36442? CVE-2020-36442 has a CVSS score of 8.1 (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 beef are affected by CVE-2020-36442? beef (rust) versions < 0.5.0 is affected.
Is there a fix for CVE-2020-36442? Yes. CVE-2020-36442 is fixed in 0.5.0. Upgrade to this version or later.
Is CVE-2020-36442 exploitable, and should I be worried? Whether CVE-2020-36442 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-2020-36442 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-2020-36442? Upgrade beef to 0.5.0 or later.