You can skip the security of the Apple OS X Yosemite operating system and gain administrative rights by using a few lines of code that fit into a tweet.
The functional Yosemite, also known as 10.10, is the latest stable version of Apple's operating system, so many will have problems with this vulnerability.
The bug which can be exploited by malicious software and hackers to gain full control of the computer, documented by well-known researcher Stefan Esser.
Everything is possible thanks to an environment variable called DYLD_PRINT_TO_FILE added to Yosemite by Apple. It specifies that within the file system an element of the operating system called dynamic linker can record error logs.
If the variable is changed with a privileged program, an attacker can arbitrarily modify files belonging to the root account, files whose change is allowed only with administrator privileges.
[tweet_embed id = 623727538234368000]These shell commands run whoami to find the username (for example iguru) and then there is "ALL = (ALL) NOPASSWD: ALL". So we have:
ALL = (ALL) NOPASSWD: ALL
Then the results through DYLD_PRINT_TO_FILE are logged and contain the list of users who can obtain root privileges: / etc / sudoers.
This line tells OS X that your user account has the ability to gain root privileges without a password accesss.
A privileged program (owned by root) runs set-uid newgrp – to get root-level access to archive sudoers.
Finally, with a sudo -s opens an interactive command-line shell, which has root privileges for the user's account thanks to the updated sudoers file.
Από εκεί και πέρα μπορείτε να κάνετε ό, τι θέλετε, να τροποποιήσετε τα έγγραφα, να εγκαταστήσετε malware, να δημιουργήσετε νέους χρήστες ή ότι άλλο σκεφτείτε.
Η ευπάθεια υπάρχει στην τελευταία έκδοση του Yosemite, OS X 10.10.4, καθώς και στη beta έκδοση 10.10.5. Εάν κάνετε αναβάθμιση στο El Capitan beta (OS X 10.11), θα είστε ασφαλής καθώς η ευπάθεια δεν υπάρχει.
For a temporary solution to affected systems, download and install it SUIDGuard of Esser.
