CVE-2021-39192

Privilege escalation: all users can access Admin-level API keys

Workarounds

• Disable all non-Administrator accounts to prevent API access.

For more information

If you have any questions or comments about this advisory:

• email us at [email protected]

Credits: Aden Yap Chuen Zhen, BAE Systems Applied Intelligence (Malaysia)

An error in the implementation of the limits service in 4.0.0 allows all authenticated users (including contributors) to view admin-level API keys via the integrations API endpoint, leading to a privilege escalation vulnerability.

Ghost(Pro) has already been patched. Self-hosters are impacted if running Ghost a version between 4.0.0 and 4.9.4. Immediate action should be taken to secure your site - see patches & workarounds below.

It is highly recommended to regenerate all API keys after patching or applying the workaround below.

The application assigns, modifies, tracks, or checks privileges incorrectly, allowing a user to gain elevated access. Typical impact: privilege escalation beyond the intended level.

CVE-2021-39192 has a CVSS score of 6.5 (Medium). The vector is network-reachable, high 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 (4.10.0); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

Fixed in 4.10.0, all 4.x sites should upgrade as soon as possible.

1. What is CVE-2021-39192? CVE-2021-39192 is a medium-severity improper privilege management vulnerability in ghost (npm), affecting versions >= 4.0.0, < 4.10.0. It is fixed in 4.10.0. The application assigns, modifies, tracks, or checks privileges incorrectly, allowing a user to gain elevated access.
2. How severe is CVE-2021-39192? CVE-2021-39192 has a CVSS score of 6.5 (Medium). 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.
3. Which versions of ghost are affected by CVE-2021-39192? ghost (npm) versions >= 4.0.0, < 4.10.0 is affected.
4. Is there a fix for CVE-2021-39192? Yes. CVE-2021-39192 is fixed in 4.10.0. Upgrade to this version or later.
5. Is CVE-2021-39192 exploitable, and should I be worried? Whether CVE-2021-39192 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
6. What actually determines whether CVE-2021-39192 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.
7. How do I fix CVE-2021-39192? Upgrade ghost to 4.10.0 or later.

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