CVE-2021-21431 is a high-severity (CVSS 8.1) Improper Input Validation vulnerability in sopel-plugins-channelmgnt. O3 Security confirms whether CVE-2021-21431 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Input Validation in sopel-plugins.channelmgnt
Real-World Exposure
sopel-plugins-channelmgntReal-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
sopel-channelmgnt is a channelmgnt plugin for sopel. In versions prior to 2.0.1, on some IRC servers, restrictions around the removal of the bot using the kick/kickban command could be bypassed when kicking multiple users at once. We also believe it may have been possible to remove users from other channels but due to the wonder that is IRC and following RfCs, We have no POC for that. Freenode is not affected. This is fixed in version 2.0.1. As a workaround, do not use this plugin on networks where TARGMAX > 1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | sopel-plugins-channelmgnt | all versions | 2.0.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sopel-plugins-channelmgnt. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update sopel-plugins-channelmgnt to 2.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-21431 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 pinpoints whether CVE-2021-21431 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2021-21431. 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-2021-21431 in your dependencies?
O3 detects CVE-2021-21431 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.