CVE-2023-38037

Active Support Possibly Discloses Locally Encrypted Files

There is a possible file disclosure of locally encrypted files in Active Support. This vulnerability has been assigned the CVE identifier CVE-2023-38037.

Versions Affected: >= 5.2.0 Not affected: < 5.2.0 Fixed Versions: 7.0.7.1, 6.1.7.5

Releases

The fixed releases are available at the normal locations.

Workarounds

To work around this issue, you can set your umask to be more restrictive like this:

$ umask 0077

ActiveSupport::EncryptedFile writes contents that will be encrypted to a temporary file. The temporary file’s permissions are defaulted to the user’s current umask settings, meaning that it’s possible for other users on the same system to read the contents of the temporary file.

Attackers that have access to the file system could possibly read the contents of this temporary file while a user is editing it.

All users running an affected release should either upgrade or use one of the workarounds immediately.

A file, directory, or other resource is assigned permissions that allow broader access than intended. Typical impact: unauthorized read, modification, or execution of the resource.

CVE-2023-38037 has a CVSS score of 5.5 (Medium). The vector is requires local access, low privileges required, and user interaction required. 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 (6.1.7.5, 7.0.7.1); upgrading removes the vulnerable code path.

Kodem intelligence

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1. What is CVE-2023-38037? CVE-2023-38037 is a medium-severity incorrect permission assignment for critical resource vulnerability in activesupport (rubygems), affecting versions >= 5.2.0, < 6.1.7.5. It is fixed in 6.1.7.5, 7.0.7.1. A file, directory, or other resource is assigned permissions that allow broader access than intended.
2. How severe is CVE-2023-38037? CVE-2023-38037 has a CVSS score of 5.5 (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 activesupport are affected by CVE-2023-38037? activesupport (rubygems) versions >= 5.2.0, < 6.1.7.5 is affected.
4. Is there a fix for CVE-2023-38037? Yes. CVE-2023-38037 is fixed in 6.1.7.5, 7.0.7.1. Upgrade to this version or later.
5. Is CVE-2023-38037 exploitable, and should I be worried? Whether CVE-2023-38037 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-2023-38037 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-2023-38037?
   • Upgrade activesupport to 6.1.7.5 or later
   • Upgrade activesupport to 7.0.7.1 or later

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