CVE-2020-13794

Impact

Hidde Smit from Cyber Eagle has discovered an User Enumeration flaw in Harbor. The issue is present in the "/users" api endpoint. This endpoint is supposed to be restricted to administrators. This restriction is able to be bypassed and information can be obtained via the "search" functionality.

Non-administrator users (such as those created via self-registration) can list all usernames and user IDs by sending a GET request to /api/users/search with parameter "username" and value "_", as follows:

curl -X GET "https://<host>/api/users/search?username=_" -H "accept: application/json" --user <user>:<password>

The vulnerability was immediately fixed by the Harbor team and all supported versions were patched. With the patched versions of Harbor, the username is required for search and we have removed the support for querying by email.

Patches

If your product uses the affected releases of Harbor, update to either version 2.1.0 or 2.0.3 to fix this issue immediately

https://github.com/goharbor/harbor/releases/tag/v2.1.0
https://github.com/goharbor/harbor/releases/tag/v2.0.3

Workarounds

There is no workaround for this issue

For more information

If you have any questions or comments about this advisory, contact [email protected]
View our security policy at https://github.com/goharbor/harbor/security/policy
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-13794

The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.

CVE-2020-13794 has a CVSS score of 4.3 (Medium). 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 (2.0.3); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2020-13794? CVE-2020-13794 is a medium-severity missing authorization vulnerability in github.com/goharbor/harbor (go), affecting versions < 2.0.3. It is fixed in 2.0.3. The application does not perform an authorization check before performing a sensitive operation.
2. How severe is CVE-2020-13794? CVE-2020-13794 has a CVSS score of 4.3 (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 github.com/goharbor/harbor are affected by CVE-2020-13794? github.com/goharbor/harbor (go) versions < 2.0.3 is affected.
4. Is there a fix for CVE-2020-13794? Yes. CVE-2020-13794 is fixed in 2.0.3. Upgrade to this version or later.
5. Is CVE-2020-13794 exploitable, and should I be worried? Whether CVE-2020-13794 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-2020-13794 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-2020-13794? Upgrade github.com/goharbor/harbor to 2.0.3 or later.