2 August 2016

Asus TP300L Touchpad Fix for Fedora 24

The following commands will help you to enable touchpad to be working fine

sudo dnf remove xorg-x11-drv-synaptics
sudo dnf install xorg-x11-drv-libinput

then you have to reboot

19 January 2016

The true reason behind group policy client error & a better way to fix it !!

When you try to login into Windows 10 from a non admin account you may receive an error as following:
Group Policy Client Service failed the sign-in
this happens when you try to logon using a non admin account in addition to some applications or drivers that were installed with admin privileges before. these applications doesn't support to work in non-elevated environment. the most widely used solution is mentioned there https://support.microsoft.com/en-us/kb/2976660 which requires from you to directly edit your windows registry. a better way which makes you not to rush into editing your registry is to know which applications you've installed with admin privileges that cause this issue. then you have to ask yourself "does this application really require admin privileges?" . the most application category that causes this issue to so many people is third party web browsers. you will also find out that your issue is most probably caused by Google Chrome web browser which doesn't require administrative privileges to get installed. so all you just need is to uninstall google chrome then reinstall it & when you get prompted to administrative privileges, just click on cancel. google chrome will continue to install with non admin mode. this is also better for the security of your windows 10 machine. so if what causes this error to you is a web browser you don't have to give it a permission with admin. however, you may need what Microsoft published if it is a driver.

16 June 2014

How to fix ZynOS vulnerability & prevent rom-0 access

This is an easy way to fix your router against rom-0 vulnerability. it can be applied to ZyNOS routers. I applied this solution to TP-Link TD-W8961ND router. it could be applied to the following list too:
  • TD-W8901G
  • TD-8816
  • TD-W8951ND
  • ZTE ZXV10 W300
rom-0 vulnerability was discovered by MrNasro. he suggested a solution but I think it is not applicable for the most devices as they don't provide a web interface to change this settings. another person (Piotr Bania) came with a different way to solve it. however it is almost impossible to apply as it requires (smart people only :) from you to open the router's case & to start reverse engineering the router's memory.

This vulnerability arise from the default settings of the firmware & it doesn't provide a way to change these settings from the web interface. luckily, the firmware does provide another access method to change the router's settings but it's not mentioned in the user manual. the second access method is the CLI which can be accomplished by using Putty or Telnet. here I used telnet from Windows. now you go with the following steps to prevent the flaw.

  • first you need to reset the router to factory default settings by pressing the reset button. you need to do this to ensure safe configuration for your router
  • go to the web interface of your router which can be accessed from & update your router setting with your ISP information
  • under maintenance change the default password from admin to anything you want & don't forget it as you will need it later on.
  • open cmd & type the following commands line by line
1 >telnet
2 Password: <type your router password>
3 Copyright (c) 2001 - 2011 TP-LINK TECHNOLOGIES CO., LTD.
4 TP-LINK> sys server load
5 TP-LINK> sys server access ftp 1
6 TP-LINK> sys server access web 1
7 TP-LINK> sys server access icmp 1
8 TP-LINK> sys server access tftp 1
9 TP-LINK> sys server access snmp 1
9 TP-LINK> sys server access telnet 2
10 TP-LINK> sys server save
11 sys server: save ok

that's all you need & now your router is safe from rom-0 attack.

CWE ID     255