D-Link DIR-615 T1 20.10 - CAPTCHA Bypass

# Exploit Title: D-Link DIR-615 T1 20.10 - CAPTCHA Bypass
# Date: 2019-10-12
# Exploit Author: huzaifa hussain
# Vendor Homepage: https://in.dlink.com/
# Version: DIR-615 T1 ver:20.10
# Tested on: D-LINK ROUTER "MODEL NO: DIR-615" with "FIRMWARE VERSION:20.10" & "HARDWARE VERSION:T1
# CVE: CVE-2019-17525

D-LINK ROUTER "MODEL NO: DIR-615" with "FIRMWARE VERSION:20.10" & "HARDWARE VERSION:T1

A vulnerability found on login-in page of D-LINK ROUTER "DIR-615" with "FIRMWARE VERSION:20.10" & "HARDWARE VERSION:T1" which allows attackers to easily bypass CAPTCHA on login page by BRUTEFORCING.

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D-Link released new firmware designed to protect against logging in to the router using BRUTEFORCING. There is a flaw in the captcha authentication system that allows an attacker to reuse the same captcha without reloading new.

ATTACK SCENARIO AND REPRODUCTION STEPS

1: Find the ROUTER LoginPage.
2: Fill the required login credentials.
3: Fill the CAPTCH properly and Intercept the request in Burpsuit.
4: Send the Request to Intruder and select the target variables i.e. username & password which will we bruteforce under Positions Tab
5: Set the payloads on target variables i.e. username & password under Payloads Tab.
5: Set errors in (the validatecode is invalid & username or password error, try again) GREP-MATCH under Options Tab.
6: Now hit the start attack and you will find the correct credentials.

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Huzaifa Hussain