CVE-2025-61583: Joni1802 Ts3 Manager XSS Vulnerability

CVE-2025-61583 Overview

CVE-2025-61583 is a reflected cross-site scripting (XSS) vulnerability in TS3 Manager, a web interface for managing Teamspeak3 servers. The flaw affects versions 2.2.1 and earlier, and stems from missing input sanitization in the login page's error handling routine. Malicious scripts embedded in server hostnames execute in the victim's browser context when rendered by the error handler. The issue is tracked under [CWE-20: Improper Input Validation] and is resolved in version 2.2.2.

Critical Impact
Attackers can craft malicious hostname payloads that execute arbitrary JavaScript in a victim's browser, enabling session theft, credential harvesting, and unauthorized actions within the TS3 Manager interface.

Affected Products

joni1802 ts3_manager versions 2.2.1 and earlier
TS3 Manager server component (packages/server/socket.js)
TS3 Manager login page error handler

Discovery Timeline

2025-10-01 - CVE-2025-61583 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-61583

Vulnerability Analysis

The vulnerability exists in the TS3 Manager login flow, where the application echoes server connection error messages back to the client without sanitization. When a user attempts to connect to a Teamspeak3 server, the supplied hostname value is reflected into the login page's error output. An attacker who controls the hostname string, either through a crafted URL or a controlled server, can inject HTML and JavaScript that the browser renders as executable code.

Because the payload runs in the origin of the TS3 Manager interface, attackers gain access to authentication cookies, JSON Web Tokens (JWTs), and any privileged actions available to the logged-in user. The Common Weakness Enumeration classifies this issue as [CWE-20].

Root Cause

The root cause is the absence of an output sanitization routine when constructing login error responses. The patch introduces a new sanatizer module in packages/server/utils/ and wires it into packages/server/socket.js. Before the fix, error strings containing user-controlled hostname data were forwarded directly to the client-side renderer.

Attack Vector

Exploitation requires user interaction. The victim must click a crafted link or connect to an attacker-controlled hostname that triggers the error path. Because the attack is network-based and requires no prior authentication, phishing campaigns are the most realistic delivery method. The Exploit Prediction Scoring System (EPSS) currently places CVE-2025-61583 in the 14.5th percentile, and no public exploit or CISA KEV listing exists.

javascript

// Patch: packages/server/socket.js
   });
   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");

// Patch: packages/server/utils/index.js
 const logger = require("./logger");
 const whitelist = require("./whitelist");
+const sanatizer = require("./sanatizer");

 module.exports = {
   logger,
   whitelist,
+  sanatizer,
 };
// Source: https://github.com/joni1802/ts3-manager/commit/3a069915f97a6f5dae1fe0b2e32aa11a69d83b5e

Detection Methods for CVE-2025-61583

Indicators of Compromise

Login attempts containing hostname parameters with <script>, onerror=, javascript:, or HTML entity-encoded payloads
HTTP referrers pointing to unfamiliar external domains that redirect users to the TS3 Manager login page
Unexpected outbound requests from browser sessions to attacker-controlled domains after visiting the login page

Detection Strategies

Inspect web server and reverse proxy logs for query strings or POST bodies targeting the login endpoint with script-like characters in the hostname field
Deploy a Content Security Policy (CSP) report-only header and monitor violation reports for inline script execution on TS3 Manager pages
Correlate authentication events with browser telemetry to identify session token access from anomalous JavaScript contexts

Monitoring Recommendations

Alert on TS3 Manager instances still running versions 2.2.1 or earlier through software inventory scans
Track JWT cookie access patterns to detect exfiltration attempts consistent with XSS payload delivery
Monitor referrer headers on login requests and flag external referrers that do not match expected user workflows

How to Mitigate CVE-2025-61583

Immediate Actions Required

Upgrade TS3 Manager to version 2.2.2 or later, which introduces the sanatizer utility on the server socket handler
Rotate any session tokens, JWT signing keys, and administrative credentials that may have been exposed during the vulnerable window
Restrict TS3 Manager access to trusted networks through firewall rules or a reverse proxy with authentication

Patch Information

The fix is available in the upstream commit joni1802/ts3-manager 3a06991 and documented in the GitHub Security Advisory GHSA-qw6j-37r6-m93g. Administrators should redeploy the server package after upgrading dependencies.

Workarounds

Place TS3 Manager behind a web application firewall (WAF) with rules that strip HTML tags and JavaScript event handlers from request parameters
Enforce a strict Content Security Policy that disallows inline scripts (script-src 'self') on the TS3 Manager interface
Educate users to avoid clicking untrusted TS3 Manager links and to verify hostnames before initiating server connections

bash

# Example nginx CSP header to reduce XSS impact
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'none'" always;
add_header X-Content-Type-Options "nosniff" always;
add_header Referrer-Policy "strict-origin-when-cross-origin" always;