Summary
RPyC's missing security check results in code execution when using numpy.array on the server-side.
An issue in Open Source: RPyC v.4.00 thru v.5.3.1 allows a remote attacker to execute arbitrary code via a crafted script to the __array__ attribute component. This vulnerability was introduced in 9f45f826.
Attack Vector
RPyC services that rely on the __array__ attribute used by numpy are impacted. When the server-side exposes a method that calls the attribute named __array__ for a a client provided netref (e.g., np.array(client_netref)), a remote attacker can craft a class which results in remote code execution
Workarounds
While the recommend fix is to upgrade to RPyC 6.0.0, the workaround is to apply bba1d356 as patch.
Affected Component
The affected component is the __array__ method constructed for NetrefClass.
References
Impact
Assuming the system exposes a method that calls the attribute __array__, an attacker can execute code using the vulnerable component.
A critical operation is accessible without requiring any authentication. Typical impact: any user can invoke the privileged function.
CVE-2024-27758 has a CVSS score of 8.5 (High). The vector is network-reachable, low 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 (6.0.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
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.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
The fix is available in RPyC 6.0.0. The major version change is because some users may need to set allow_pickle to True when migrating to RPyC 6.
Frequently Asked Questions
- What is CVE-2024-27758? CVE-2024-27758 is a high-severity missing authentication for critical function vulnerability in rpyc (pip), affecting versions >= 4.0.0, < 6.0.0. It is fixed in 6.0.0. A critical operation is accessible without requiring any authentication.
- How severe is CVE-2024-27758? CVE-2024-27758 has a CVSS score of 8.5 (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 rpyc are affected by CVE-2024-27758? rpyc (pip) versions >= 4.0.0, < 6.0.0 is affected.
- Is there a fix for CVE-2024-27758? Yes. CVE-2024-27758 is fixed in 6.0.0. Upgrade to this version or later.
- Is CVE-2024-27758 exploitable, and should I be worried? Whether CVE-2024-27758 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-2024-27758 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-2024-27758? Upgrade
rpycto 6.0.0 or later.