GHSA-38wq-6q2w-hcf9 — rucio-webui
MEDIUMGHSA-38wq-6q2w-hcf9 is a medium-severity (CVSS 5.3) CWE-204 vulnerability in rucio-webui. A fix is available for rucio-webui — see the affected versions and patch details below.
Rucio WebUI has Username Enumeration via Login Error Message
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 GHSA-38wq-6q2w-hcf9.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-38wq-6q2w-hcf9 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
rucio-webui🐍rucio-webui🐍rucio-webuiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The WebUI login endpoint returns distinct error messages depending on whether a supplied username exists, allowing unauthenticated attackers to enumerate valid usernames.
Details
When submitting invalid credentials to /ui/login, the WebUI responds with different error messages based on the existence of the provided username (identity). A non-existent username results in an error indicating that no account is associated with the identity, while an existing username with an incorrect password produces a different authentication-related error.
This behavioral difference allows an attacker to distinguish valid usernames from invalid ones by observing the response content.
Proof of Concept
Bogus Login (Non-existent Username "15251087")
Response contains:
Cannot get find any account associated with 15251087 identity.
Bogus Login (Existing Username "root", Wrong Password)
Response contains:
Cannot get auth token. It is possible that the presented identity root is not mapped to any Rucio account root.
The difference in error messages confirms whether a username exists.
Impact
An unauthenticated attacker can enumerate valid usernames, which may be leveraged for targeted password guessing, credential stuffing, or social engineering attacks.
Remediation / Mitigation
Return a generic authentication failure message for all login errors, regardless of whether the username exists. Avoid disclosing account or identity existence through error responses. Consider implementing rate limiting or additional login throttling to further reduce abuse.
Reources:
- OWASP Authentication Cheat Sheet - Authentication and Error Messages: https://cheatsheetseries.owasp.org/cheatsheets/Authentication_Cheat_Sheet.html#authentication-and-error-messages
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | rucio-webui | all versions | 35.8.3pip install --upgrade 'rucio-webui==35.8.3' |
| 🐍PyPI | rucio-webui | ≥ 36.0.0rc1&&< 38.5.4 | 38.5.4pip install --upgrade 'rucio-webui==38.5.4' |
| 🐍PyPI | rucio-webui | ≥ 39.0.0rc1&&< 39.3.1 | 39.3.1pip install --upgrade 'rucio-webui==39.3.1' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rucio-webui, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update rucio-webui to 35.8.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-38wq-6q2w-hcf9 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-38wq-6q2w-hcf9 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-38wq-6q2w-hcf9. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-38wq-6q2w-hcf9 in your dependencies?
O3 Security finds GHSA-38wq-6q2w-hcf9 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.