CVE-2025-61582 is a denial of service (DoS) vulnerability classified under CWE-20 (Improper Input Validation) found in the ts3-manager web interface, a tool used to maintain Teamspeak3 servers. The flaw exists in versions 2.2.1 and earlier, where the application fails to properly validate and handle Unicode tag characters submitted in the Server field on the login page. Specifically, during the ASCII conversion process, these Unicode inputs cause an unhandled exception that crashes the application within four to five seconds. This vulnerability can be exploited remotely by an unauthenticated attacker without any privileges or user interaction, simply by sending specially crafted input to the login interface. The impact is a complete denial of service, rendering the ts3-manager interface unavailable and potentially disrupting Teamspeak3 server management. The vulnerability was publicly disclosed on October 1, 2025, with a CVSS v3.1 base score of 7.5, indicating high severity. The issue is resolved in version 2.2.2 of ts3-manager, which properly validates input to prevent the crash. No known exploits have been reported in the wild as of the publication date.

For European organizations relying on ts3-manager to administer Teamspeak3 servers, this vulnerability poses a significant risk of service disruption. The denial of service can interrupt communication channels critical for gaming communities, corporate VoIP setups, or other collaboration environments using Teamspeak3. This could lead to operational downtime, loss of productivity, and reputational damage, especially for service providers or enterprises with real-time communication dependencies. Since exploitation requires no authentication and minimal effort, attackers can easily cause repeated outages or use this as a distraction while attempting other attacks. The impact is primarily on availability, with no direct confidentiality or integrity compromise reported. However, persistent denial of service can indirectly affect business continuity and user trust.

The primary mitigation is to upgrade ts3-manager to version 2.2.2 or later, where the input validation flaw has been fixed. Organizations should immediately apply this update to eliminate the vulnerability. Additionally, implementing web application firewalls (WAFs) with rules to detect and block suspicious Unicode input patterns targeting the Server field can provide a temporary protective layer. Network-level rate limiting and IP reputation filtering can reduce the risk of automated exploitation attempts. Monitoring application logs for repeated failed login attempts with unusual Unicode characters can help detect exploitation attempts early. Finally, organizations should review and harden input validation routines in custom or third-party web interfaces to prevent similar issues.