A classic buffer overflow occurs in FortiSwitchAXFixed firmware when copying input without size validation, allowing an unauthenticated attacker on the same adjacent network to send a crafted LLDP packet that can lead to execution of arbitrary code or commands on the device. This flaw is classified as CWE-120, a classic buffer overflow weakness, and can compromise the confidentiality, integrity, and availability of the switch by granting full control to the attacker.

Fortinet FortiSwitchAXFixed devices running firmware versions 1.0.0 through 1.0.1 are affected. The vulnerability is not present in upgrades to FortiSwitchAX-Chassis 1.0.0 or newer, nor in FortiSwitchAXFixed 1.0.2 and later.

The vulnerability carries a CVSS score of 7.7, indicating a high severity. Its EPSS score is less than 1%, suggesting that widespread exploitation is currently unlikely. The flaw is not listed in the CISA Known Exploited Vulnerabilities catalog. The attack vector is inferred to be local: an adversary must be on the same adjacent network to craft and transmit the malicious LLDP packet. If exploited, the attacker could gain unauthorized command execution on the affected device.