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Libuser roothelper Privilege Escalation

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Libuser roothelper Privilege Escalation



This module attempts to gain root privileges on Red Hat based Linux systems, including RHEL, Fedora and CentOS, by exploiting a newline injection vulnerability in libuser and userhelper versions prior to 0.56.13-8 and version 0.60 before 0.60-7. This module makes use of the roothelper.c exploit from Qualys to insert a new user with UID=0 in /etc/passwd. Note, the password for the current user is required by userhelper. Note, on some systems, such as Fedora 11, the user entry for the current user in /etc/passwd will become corrupted and exploitation will fail. This module has been tested successfully on libuser packaged versions 0.56.13-4.el6 on CentOS 6.0 (x86_64); 0.56.13-5.el6 on CentOS 6.5 (x86_64); 0.60-5.el7 on CentOS 7.1-1503 (x86_64); 0.56.16-1.fc13 on Fedora 13 (i686); 0.59-1.fc19 on Fedora Desktop 19 (x86_64); 0.60-3.fc20 on Fedora Desktop 20 (x86_64); 0.60-6.fc21 on Fedora Desktop 21 (x86_64); 0.60-6.fc22 on Fedora Desktop 22 (x86_64); 0.56.13-5.el6 on Red Hat 6.6 (x86_64); and 0.60-5.el7 on Red Hat 7.0 (x86_64). RHEL 5 is vulnerable, however the installed version of glibc (2.5) is missing various functions required by roothelper.c.


  • Qualys
  • bcoles <bcoles@gmail.com>




x86, x64


Module Options

To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':

msf > use exploit/linux/local/libuser_roothelper_priv_esc
msf exploit(libuser_roothelper_priv_esc) > show targets
msf exploit(libuser_roothelper_priv_esc) > set TARGET < target-id >
msf exploit(libuser_roothelper_priv_esc) > show options
    ...show and set options...
msf exploit(libuser_roothelper_priv_esc) > exploit

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– Jim O’Gorman | President, Offensive Security