CVE-2025-61582: Joni1802 Ts3 Manager DoS Vulnerability

CVE-2025-61582 Overview

CVE-2025-61582 is a Denial of Service (DoS) vulnerability affecting TS3 Manager, a modern web interface for maintaining TeamSpeak3 servers. The vulnerability allows an unauthenticated attacker to crash the application through the submission of specially crafted Unicode input to the Server field on the login page. No prior authentication or privileges are required to exploit this flaw, making it particularly dangerous for publicly accessible installations.

The vulnerability manifests when Unicode tag characters are submitted during the login process. The application fails to properly handle these characters during the ASCII conversion process, resulting in an unhandled exception that terminates the application within four to five seconds of submission.

Critical Impact

Unauthenticated attackers can crash TS3 Manager instances remotely with minimal effort, causing service disruption for TeamSpeak3 server administrators.

Affected Products

• TS3 Manager versions 2.2.1 and earlier
• joni1802 ts3_manager (all versions prior to 2.2.2)

Discovery Timeline

• 2025-10-01 - CVE-2025-61582 published to NVD
• 2025-10-20 - Last updated in NVD database

Technical Details for CVE-2025-61582

Vulnerability Analysis

This vulnerability falls under CWE-20 (Improper Input Validation). The TS3 Manager application processes user-supplied input from the Server field on the login page without adequate validation or sanitization of Unicode characters. When special Unicode tag characters are submitted, the application attempts to convert them to ASCII format but lacks proper exception handling for characters that cannot be converted.

The attack requires no authentication, meaning any network-accessible TS3 Manager installation can be targeted. The application terminates completely within seconds of receiving malicious input, requiring administrator intervention to restore service.

Root Cause

The root cause is insufficient input sanitization in the server connection handling code. The application directly processes user-supplied server addresses without first validating or sanitizing Unicode characters. When the ASCII conversion routine encounters Unicode tag characters that have no ASCII equivalent, an unhandled exception is thrown, which propagates up the call stack and terminates the Node.js process.

Attack Vector

The attack vector is network-based and requires no user interaction. An attacker can craft a malicious request containing Unicode tag characters and submit it to the Server field on the login page. The attack can be automated and repeated to maintain a persistent denial of service condition.

The fix introduced a sanatizer utility module to properly handle input validation:

   });
   const crypto = require("crypto");
   const jwt = require("jsonwebtoken");
-  const { logger, whitelist } = require("./utils");
+  const { logger, whitelist, sanatizer } = require("./utils");
   const cookie = require("cookie");
   const { TeamSpeak } = require("ts3-nodejs-library");

Source: GitHub Commit

The sanitizer module was added to the utility exports:

 const logger = require("./logger");
 const whitelist = require("./whitelist");
+const sanatizer = require("./sanatizer");
 
 module.exports = {
   logger,
   whitelist,
+  sanatizer,
 };

Source: GitHub Commit

Detection Methods for CVE-2025-61582

Indicators of Compromise

• Unexpected TS3 Manager application crashes or restarts
• Web server logs showing unusual POST requests to the login endpoint containing non-ASCII characters
• Repeated process termination events in system logs for the TS3 Manager Node.js process
• HTTP requests with Unicode tag characters (U+E0000 to U+E007F range) in the Server field parameter

Detection Strategies

• Monitor application logs for unhandled exception errors related to ASCII conversion or string encoding
• Implement web application firewall (WAF) rules to detect and block requests containing Unicode tag characters
• Set up process monitoring to alert on unexpected TS3 Manager restarts
• Review HTTP access logs for suspicious login page requests with abnormal character encodings

Monitoring Recommendations

• Configure application uptime monitoring with alerting for service interruptions
• Enable detailed error logging in TS3 Manager to capture exception stack traces
• Deploy network traffic analysis to identify repeated malicious login attempts
• Implement rate limiting on the login endpoint to reduce the impact of automated attacks

How to Mitigate CVE-2025-61582

Immediate Actions Required

• Upgrade TS3 Manager to version 2.2.2 or later immediately
• Restrict network access to TS3 Manager installations using firewall rules or VPN
• Monitor for application crashes and implement automatic restart mechanisms as a temporary measure
• Review access logs for any exploitation attempts prior to patching

Patch Information

The vulnerability is fixed in TS3 Manager version 2.2.2. The patch introduces a sanitizer module that properly validates and sanitizes user input before processing. The fix can be reviewed in the GitHub commit 3a06991. Additional details are available in the GitHub Security Advisory GHSA-4cq4-hp4f-8w7p.

Workarounds

• Place TS3 Manager behind a reverse proxy with input filtering capabilities to strip Unicode tag characters
• Implement network-level access controls to restrict login page access to trusted IP addresses only
• Configure process supervision (e.g., systemd, PM2) to automatically restart the application if it crashes
• Use a web application firewall to block requests containing suspicious Unicode sequences

# Example: Configure PM2 for automatic restart
pm2 start ts3-manager --name ts3-manager --restart-delay=5000 --max-restarts=10
pm2 save