Lantronix SLC8000 and related devices contain an SSRF vulnerability in the WebSSH/WebTelnet listener component. The custom shellinaboxd service uses the rooturl parameter from incoming web connections to determine its IP address. By manipulating this parameter, an unauthenticated attacker can cause the device to establish SSH connections to attacker-controlled endpoints. This allows the attacker to enumerate or communicate with internal network resources that would otherwise be unreachable. The issue affects all firmware versions of SLB882 and firmware versions prior to 9.7.0.3 for SLC8000 and prior to 9.7.0.1 for EMG8500/EMG7500. The vulnerability has a CVSS 4.0 base score of 7.7 (high severity). No official patch or remediation details are provided in the source data.

An unauthenticated attacker can exploit this SSRF vulnerability to make the affected device initiate SSH connections to arbitrary hosts. This can be used to probe or interact with internal network systems that are normally inaccessible from outside, potentially aiding further attacks or reconnaissance. The vulnerability does not require user interaction or privileges and has a high severity rating.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict access to the WebSSH/WebTelnet listener interfaces to trusted networks only and monitor for unusual SSH connection attempts originating from the device.