CVE-2021-3707 D-Link DSL-2750U Router Unauthorized Configuration Modification Vulnerability

Introduction

D-Link DSL-2750U router with firmware vME1.16 or prior versions is vulnerable to unauthorized configuration modification.

Exploit

Export configuration file from a DSL-2750U router whose password is known.

Connect to the tftp server on router whose password is not known and send the configuration file containing known password.

tftp 192.168.1.1
binary
put cfg.xml

All configuration, including the password of the router will be changed to that in uploaded configuration file.



Video



Comments

Post a Comment

Popular posts from this blog

Extract / Create Cramfs File System from Ubuntu 20.04

Image
Extract Cramfs Check the endianness of the Cramfs file: file cramfs  This is a big endian file. Convert cramfs  file to little endian file cramfs_le using cramfsswap. cramfsswap cramfs cramfs_le Extract the little endian file  cramfs_le to folder fs using fsck.cramfs. sudo fsck.cramfs --extract=fs cramfs_le Create Cramfs Use mkfs.cramfs to create Cramfs file system from the contents of folder fs .To create a little endian file system: sudo mkfs.cramfs fs cramfs_new For big endian Cramfs file system: sudo mkfs.cramfs -N big fs cramfs_new Video
Read more

Firmadyne Installation & Emulation of Firmware

Image
 Introduction Firmadyne can be used to perform emulation and analysis of Linux based firmware. Installation Install Ubuntu 18.04 LTS and upgrade all packages: sudo apt update sudo apt upgrade Install and configure other packages: sudo apt-get install busybox-static fakeroot git dmsetup kpartx netcat-openbsd nmap python3-psycopg2 snmp uml-utilities util-linux vlan python3-pip python3-magic sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 10 git clone --recursive https://github.com/firmadyne/firmadyne.git git clone https://github.com/ReFirmLabs/binwalk.git cd binwalk sudo ./deps.sh sudo python ./setup.py install cd .. sudo apt-get install postgresql sudo -u postgres createuser -P firmadyne Give firmadyne as password. sudo -u postgres createdb -O firmadyne firmware sudo -u postgres psql -d firmware < ./firmadyne/database/schema cd firmadyne ./download.sh sudo apt-get install qemu-system-arm qemu-system-mips qemu-system-x86 qemu-utils nano firmadyne.config Unco
Read more

Dump memory to file from U-Boot console using Memory Display (md) log

Image
 Introduction Dump firmware or other contents from memory of a device with U-Boot bootloader to a file by converting output of memory display (md) command to binary image.  Steps 1. Connect to U-Boot console using picocom and save all outputs in a log file using commad given below. Here the output is saved to log file named 'mdb.log'. sudo picocom /dev/ttyUSB0 --baud 115200 --logfile mdb.log 2. Display the contents of the memory using command: md.b <address> <length> Figure below shows the command to display memory contents from address 0x400000000 and of length 0x20000 (128KB) . The data in this example corresponds to a jffs2 file system. 3. Once the execution completes, edit the log file and remove everything other than md.b output. 4. Clone the github project uboot-mdb-dump.git git clone https://github.com/gmbnomis/uboot-mdb-dump.git 5. Generate the binary image file 'output.bin' from log file 'mdb.log'. python3 uboot-mdb-dump/uboot_mdb_to_image.p
Read more