From this webpage screenshot, the following key information about the vulnerability can be obtained: 1. Vulnerability Type: Denial of Service (DoS) 2. Description: - Devices exposed to the external network are detected via DDNS, and their IP addresses and ports are obtained. - By using special usernames and special characters (such as half-brackets or square brackets) to invoke the login interface, the session management program crashes, preventing users from logging into the device. 3. Affected Products: - MT6000/X3000/XE3000/A1300/AX1800/AXT1800/MT2500/MT3000/XE300/X750/SFT1200/AR300M/AR300M16/AR750/AR750S/B1300/MT1300/MT300N-V2 4. Affected Firmware Versions: - MT6000: 4.5.6, fixed in 4.5.8 - AX1800/AXT1800/MT2500/MT3000/A1300: 4.5.0, fixed in 4.5.16 - X3000: 4.4.6, fixed in 4.4.8 - XE3000: 4.4.4, fixed in 4.4.8 - XE300: 4.3.16, fixed in 4.3.17 - X750/SFT1200: 4.3.7, fixed in 4.3.11 - AR300M/AR300M16/AR750/AR750S/B1300/MT1300/MT300N-V2: 4.3.10, fixed in 4.3.11 5. Exploitation Method: - Use any network device detection website to scan for devices. - Obtain the exposed IP addresses and ports of the devices. - Invoke the login interface using special usernames and special characters (such as half-brackets or square brackets). 6. Impact: - Attackers can exploit this vulnerability by invoking the login interface and inputting special characters (such as half-brackets or square brackets), causing the session management program to crash and rendering the device inaccessible to users. This information helps in understanding the nature of the vulnerability, its scope of impact, and how it can be exploited in an attack.