The example of the backdoor found in certain versions of Webmin clearly illustrates the risk, as shown in the video below: a vulnerability or compromised component can grant root access to the machine hosting the console. Alarmingly, you don’t need to be an expert to exploit this type of flaw—an inexperienced attacker, or even a “script kiddie” with minimal knowledge, can easily take advantage of it. Not to mention public bots that constantly scan the web for exposed interfaces and known vulnerabilities.
Forgotten administration consoles are a veritable goldmine for attackers: they are often outdated, unpatched, and poorly monitored. From a single initial access point, an intruder can escalate privileges, move laterally across the network, install persistence mechanisms, exfiltrate data, or deploy ransomware. In short, a single poorly protected console is often enough to turn a local intrusion into a full compromise of the IT system.
And when a former employee knows it too, it becomes a silent—but very real—vulnerability.