D-Link DIR-600L B1 Hardcoded Telnet Backdoor Credentials

D-Link DIR-600L Hardware Revision B1 (End-of-Life) contains a hardcoded telnet backdoor. The device starts a telnet daemon at boot via /bin/telnetd.sh with the username "Alphanetworks" and the static password "wrgn61_dlwbr_dir600L" read from /etc/alpha_config/image_sign. The custom telnetd binary accepts a -u user:password flag, and the custom login binary uses strcmp() to validate credentials. Successful authentication grants an unauthenticated attacker on the local network a root shell with full administrative control.  The device has reached End-of-Life (EOL) and will not receive patches.

D-Link DIR-600L A1 Hardcoded Telnet Backdoor Credentials

D-Link DIR-600L Hardware Revision A1 (End-of-Life) contains a hardcoded telnet backdoor. The device starts a telnet daemon at boot via /bin/telnetd.sh with the username "Alphanetworks" and the static password "wrgn35_dlwbr_dir600l" read from /etc/alpha_config/image_sign. The custom telnetd binary accepts a -u user:password flag, and the custom login binary uses strcmp() to validate credentials. Successful authentication grants an unauthenticated attacker on the local network a root shell with full administrative control. The device has reached End-of-Life (EOL) and will not receive patches.

D-Link DIR-600 ssdp.cgi command injection

A vulnerability was identified in D-Link DIR-600 up to 2.15WWb02. This vulnerability affects unknown code of the file ssdp.cgi. Such manipulation of the argument HTTP_ST/REMOTE_ADDR/REMOTE_PORT/SERVER_ID leads to command injection. The attack may be launched remotely. The exploit is publicly available and might be used. This vulnerability only affects products that are no longer supported by the maintainer.

D-Link DIR-110/412/600/615/645/815 RCE via service.cgi

Multiple D-Link DIR-series routers, including DIR-110, DIR-412, DIR-600, DIR-610, DIR-615, DIR-645, and DIR-815 firmware version 1.03, contain a vulnerability in the service.cgi endpoint that allows remote attackers to execute arbitrary system commands without authentication. The flaw stems from improper input handling in the EVENT=CHECKFW parameter, which is passed directly to the system shell without sanitization. A crafted HTTP POST request can inject commands that are executed with root privileges, resulting in full device compromise. These router models are no longer supported at the time of assignment and affected version ranges may vary. Exploitation evidence was first observed by the Shadowserver Foundation on 2025-08-21 UTC.

D-Link Devices Unauthenticated RCE

The web interface of multiple D-Link routers, including DIR-600 rev B (≤2.14b01) and DIR-300 rev B (≤2.13), contains an unauthenticated OS command injection vulnerability in command.php, which improperly handles the cmd POST parameter. A remote attacker can exploit this flaw without authentication to spawn a Telnet service on a specified port, enabling persistent interactive shell access as root.

D-Link Devices command.php Unauthenticated RCE

An OS command injection vulnerability exists in various legacy D-Link routers—including DIR-300 rev B and DIR-600 (firmware ≤ 2.13 and ≤ 2.14b01, respectively)—due to improper input handling in the unauthenticated command.php endpoint. By sending specially crafted POST requests, a remote attacker can execute arbitrary shell commands with root privileges, allowing full takeover of the device. This includes launching services such as Telnet, exfiltrating credentials, modifying system configuration, and disrupting availability. The flaw stems from the lack of authentication and inadequate sanitation of the cmd parameter.

D-Link DIR-600 HTTP Header hedwig.cgi stack-based overflow

A vulnerability was found in D-Link DIR-600 up to 2.15WWb02. Affected by this vulnerability is an unknown functionality of the file hedwig.cgi of the component HTTP Header Handler. The manipulation of the argument Cookie results in stack-based buffer overflow. It is possible to launch the attack remotely. The exploit has been made public and could be used. This vulnerability only affects products that are no longer supported by the maintainer.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formSetMACFilter.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formAdvFirewall.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formSetRoute.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formLogDnsquery.

D-Link DIR600LAx FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formSetQoS.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formAdvNetwork.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formSetWAN_Wizard7.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formLanSetupRouterSettings.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formAutoDetecWAN_wizard4.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formEasySetTimezone.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the next_page parameter in the function formDeviceReboot.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formSetWAN_Wizard52.

D-Link DIR600L Ax FW116WWb01 was discovered to contain a buffer overflow via the curTime parameter in the function formTcpipSetup.