Hack Linux Kernel using Dirtycow Exploit (Privilege Escalation)
People say that “good things take time” but everyone knows that in today’s world everyone has everything but time especially in cyber security and hacking. But worry no more about time as we are going to present the best and time saving method to hack any Linux server/machine through DirtyCow. This is the latest vulnerability that has been found that works against every version of kernel that has ever existed till date and researchers and attackers are taking it very seriously. It’s a nine year old bug but is only discovered now. And it has already begun to be used as leverage against the digital world.
DirtyCow is the latest exploit coined against every version of kernel in Linux. It got its name as “Cow” because it works on Copy-on-Write breakage. Kernel’s memory system works by handling Copy-On-Write breakage which contains private ROM. So basically this exploit helps us to escalate privileges by modifying existing setuid files.
Now I am going to walk you through the practical of DirtyCow by creating a normal user in my Kali and then I will be guiding you through the whole practical so stay with me. The vulnerability was discovered by security researcher Phil Oester, Link Here
Firstly make a new user in your kali by typing:
useradd –m raj
After running the above two commands it will ask you about password, here, give any password and repeat it.
Once your password is updated successfully and and user is created log into the Kali through that new user and then go to this link à https://github.com/gbonacini/CVE-2016-5195 and download the zip file.
After the downloading is done, open the zip file. Here you will find a folder; open that folder in the terminal. Now in the terminal will notice that you do not have administrative privileges and to confirm this just type:
After this lets check the list of directories in the folder and for that type:
And then run dcow file by typing:
Executing the above command will show you the password. Copy this password and then type :
Then give the same password that you copied when asked.
And VOILA!!! You have the access to the root!!
Conclusion: Using this we are modifying Copy-On-Write cache in kernel. By modifying we are changing contents of any readable and mapable file. It can alter any file but that changes affect cache memory only that means after rebooting the changes will be back to normal. Hence, letting us have the access to root.