Across Asia and other regions, cybersecurity experts are raising alarms about the persistent risk posed by exposed Telnet services — an outdated network protocol that continues to leave systems vulnerable to attackers, even as defenders struggle to fully contain the threat.

Recent research shows that a critical vulnerability in the GNU InetUtils Telnet server (tracked as CVE-2026-24061) has put roughly 800,000 Telnet servers worldwide at risk of remote attack, and a significant share — about 380,000 — are located in Asia.

Why Telnet Is Still a Problem

Telnet was developed decades ago for remote access to servers, but unlike modern protocols such as SSH, it transmits usernames and passwords in plain text, giving attackers an easy opportunity to intercept credentials or exploit weaknesses remotely.

The newly disclosed vulnerability allows attackers to bypass authentication entirely and gain root-level control of affected systems if administrators haven’t patched or disabled the service — a scenario that researchers say is being actively probed by threat actors.

Obstacles in Blocking Telnet Threats in Asia

Even as the security risk has become clear, many organisations in Asia struggle to block or eliminate Telnet exposures for several reasons:

• Legacy Systems and IoT Devices: Many older network appliances, industrial controllers, and Internet of Things devices in the region still run Telnet for remote management, and these often lack vendor support or easy patch mechanisms.

• Limited Visibility and Asset Management: Organisations without comprehensive asset inventories may not even know where Telnet services are exposed, making it difficult to prioritise mitigation.

• Cybersecurity Resource Gaps: Broader regional readiness challenges — including shortages of skilled security professionals and reactive approaches to cyber threats — mean many teams focus on immediate attacks rather than proactively eliminating legacy risks that protocols like Telnet present. Studies show that many Asia-Pacific organisations spend most of their time responding to threats rather than preventing them.

The Real-World Risk

The prevalence of exposed Telnet services creates an enticing attack surface for cybercriminals and espionage groups alike. Once attackers gain control through an unpatched Telnet server, they can install malware, steal data, or pivot deeper into networks, posing serious risks to businesses, critical infrastructure, and government systems.

What It Takes to Defend Against Telnet Threats

Experts recommend that organisations in Asia and beyond:

• Disable Telnet entirely wherever possible and switch to secure alternatives like SSH.

• Patch vulnerable systems promptly, especially those running outdated telnetd implementations.

• Block TCP port 23 (used by Telnet) at network perimeters to prevent external access.

• Inventory legacy and IoT devices to ensure they’re accounted for in security plans and aren’t inadvertently exposing services.

A Broader Cybersecurity Challenge

The Telnet issue highlights a larger truth: Asia’s digital infrastructure is evolving rapidly, but older technologies and insufficient defensive practices continue to undermine cybersecurity efforts. Closing these legacy gaps while building proactive security capabilities is essential — not just to block specific threats like Telnet exploits, but to improve overall resilience against a growing range of cyberattacks in the region.