CVE-2021-32645 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in hyn/multi-tenant. A fix is available for hyn/multi-tenant — see the affected versions and patch details below.
Open Redirect
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
CVE-2021-32645 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 378,567 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
hyn/multi-tenantReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Impact
In some situations, it is possible to have open redirects where users can be redirected from your site to any other site using a specially crafted URL.
This is only the case for installations where the default Hostname Identification is used and the environment uses tenants that have force_https set to true (default: false)
Patches
Version 5.7.2 contains the relevant patches to fix this bug. Stripping the URL from special characters to prevent specially crafted URL's from being redirected to.
Workarounds
There is a simple way to work around the security issue
- Set the
force_httpsto every tenant tofalse
References
https://nvd.nist.gov/vuln/detail/CVE-2018-11784
For more information
If you have any questions or comments about this advisory:
- Contact us in Discord: https://tenancy.dev/chat
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | hyn/multi-tenant | ≥ 5.6.0&&< 5.7.2 | 5.7.2composer require hyn/multi-tenant:^5.7.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hyn/multi-tenant, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update hyn/multi-tenant to 5.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-32645 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 CVE-2021-32645 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2021-32645. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2021-32645 in your dependencies?
O3 Security finds CVE-2021-32645 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.