CVE-2021-25973 is a medium-severity (CVSS 6.5) CWE-285 vulnerability in publify_core. A fix is available for publify_core — see the affected versions and patch details below.
Publify `guest` role users can self-register even when the admin does not allow it
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2021-25973.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-25973 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
publify_coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
In Publify, 9.0.0.pre1 to 9.2.4 are vulnerable to Improper Access Control. guest role users can self-register even when the admin does not allow it. This happens due to front-end restriction only.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | publify_core | ≥ 9.0.0.pre1&&< 9.2.5 | 9.2.5bundle update publify_core --conservative |
Affected Products
publifypublify_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for publify_core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update publify_core to 9.2.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-25973 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2021-25973 in your dependencies?
Find it across RubyGems, including transitive dependencies.