CVE-2021-21431
📋 TL;DR
This vulnerability in the sopel-channelmgnt plugin allows attackers to bypass restrictions and kick the bot from IRC channels when kicking multiple users simultaneously on certain IRC servers. It may also enable removing users from other channels. Users of sopel-channelmgnt plugin versions before 2.0.1 on IRC networks with TARGMAX > 1 are affected.
💻 Affected Systems
- sopel-channelmgnt plugin for sopel IRC bot
📦 What is this software?
Channelmgnt by Mirahezebots
⚠️ Risk & Real-World Impact
Worst Case
Attackers could remove the bot from protected channels, potentially disrupting channel management and moderation capabilities, and possibly remove legitimate users from other channels.
Likely Case
Malicious users could kick the bot from channels where it should be protected, disrupting automated moderation and management functions.
If Mitigated
With proper controls, the bot remains protected and channel management functions continue normally.
🎯 Exploit Status
Exploitation requires IRC channel access and ability to issue kick commands. No public proof-of-concept available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.0.1
Vendor Advisory: https://github.com/MirahezeBots/sopel-channelmgnt/security/advisories/GHSA-23c7-6444-399m
Restart Required: Yes
Instructions:
1. Update sopel-channelmgnt plugin to version 2.0.1 or later using pip: 'pip install --upgrade sopel-plugins.channelmgnt>=2.0.1' 2. Restart the sopel bot to apply the update.
🔧 Temporary Workarounds
Avoid vulnerable IRC networks
allDo not use the channelmgnt plugin on IRC networks where TARGMAX > 1
🧯 If You Can't Patch
- Disable the channelmgnt plugin entirely if patching is not possible
- Restrict bot access to trusted channels only and monitor for unauthorized kick attempts
🔍 How to Verify
Check if Vulnerable:
Check the installed version of sopel-channelmgnt plugin. If version is below 2.0.1 and used on IRC networks with TARGMAX > 1, the system is vulnerable.Check Version:
pip show sopel-plugins.channelmgnt | grep VersionVerify Fix Applied:
Verify that sopel-channelmgnt version is 2.0.1 or higher using 'pip show sopel-plugins.channelmgnt'📡 Detection & Monitoring
Log Indicators:
- Unexpected bot kick events from channels where it should be protected
- Multiple user kick attempts in single commands
Network Indicators:
- IRC protocol traffic showing KICK commands targeting the bot with multiple targets
SIEM Query:
Search for IRC logs containing 'KICK' commands with multiple targets where the bot is one of the targets🔗 References
- https://github.com/MirahezeBots/sopel-channelmgnt/commit/7c96d400358221e59135f0a0be0744f3fad73856
- https://github.com/MirahezeBots/sopel-channelmgnt/security/advisories/GHSA-23c7-6444-399m
- https://pypi.org/project/sopel-plugins.channelmgnt/
- https://github.com/MirahezeBots/sopel-channelmgnt/commit/7c96d400358221e59135f0a0be0744f3fad73856
- https://github.com/MirahezeBots/sopel-channelmgnt/security/advisories/GHSA-23c7-6444-399m
- https://pypi.org/project/sopel-plugins.channelmgnt/
