A stack-based buffer overflow arises when an authenticated user sends an undocumented mfc eeprom read command to the device’s terminal or CLI interface. The command copies user‑provided data without bounds into a fixed‑size buffer on the stack and then passes it to a system() call. Because the input length is unchecked, the attacker can overflow the stack and overwrite the return address, leading to arbitrary code execution. The vulnerability impacts LANTRONIX devices such as SLC8000 and SLC9000 before firmware v9.7.0.2, EMG8500 and EMG7500 before v9.7.0.1, and all firmware versions of SLB882, SLCx‑02, and SLCx‑03, potentially granting the attacker full control over the device and causing loss of confidentiality, integrity, and availability, including downstream serial‑attached equipment.

Affected models include LANTRONIX EMG7500 and EMG8500 devices with firmware earlier than 9.7.0.1, all versions of the SLB882, SLCx‑02, and SLCx‑03 series, and SLC8000 and SLC9000 devices using firmware prior to 9.7.0.2. Firmware updates published by Lantronix for these families address the overflow.

The CVSS score is 9.4, marking the issue as critical. The EPSS score is 0.00848 (less than 1%) and the vulnerability has not yet appeared in the CISA KEV catalog. Attack requires authenticated access through the device’s terminal or CLI interface, meaning it is an authenticated local or remote network attack depending on management connectivity. When exploited, the attacker can achieve full control over the affected device and any downstream serial‑attached equipment.