CVE-2020-29565 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in horizon. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for horizon — see the affected versions and patch details below.
OpenStack Horizon Open redirect in workflow forms
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
horizon🐍horizon🐍horizon🐍horizonReal-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
An issue was discovered in OpenStack Horizon before 15.3.2, 16.x before 16.2.1, 17.x and 18.x before 18.3.3, 18.4.x, and 18.5.x. There is a lack of validation of the "next" parameter, which would allow someone to supply a malicious URL in Horizon that can cause an automatic redirect to the provided malicious URL.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | horizon | all versions | 15.3.2pip install --upgrade 'horizon==15.3.2' |
| 🐍PyPI | horizon | ≥ 16.0.0&&< 16.2.1 | 16.2.1pip install --upgrade 'horizon==16.2.1' |
| 🐍PyPI | horizon | ≥ 17.0.0&&< 18.3.3 | 18.3.3pip install --upgrade 'horizon==18.3.3' |
| 🐍PyPI | horizon | ≥ 18.4.0&&< 18.6.0 | 18.6.0pip install --upgrade 'horizon==18.6.0' |
Affected Products
debian linuxdebianhorizonopenstackResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for horizon, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update horizon to 15.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-29565 is resolved across your whole dependency graph.
Workarounds
Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2020-29565 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat OpenStack Platform 13.0 (Queens) | python-django-horizon-1:13.0.3-7.el7ost | RHSA-2020:5572 |
| Red Hat OpenStack Platform 16.1 | python-django-horizon-1:16.2.1-1.20201114033610.el8ost | RHSA-2020:5411 |
Frequently Asked Questions
Is CVE-2020-29565 in your dependencies?
Find it across PyPI, including transitive dependencies.