Debian (maybe other derivates |KUDUBUTUNTU|) OpenSSH Remote -=Authenticated=- SELinux Privilege Elevation

vendor:

OpenSSH

by:

Kingcope

7.2

CVSS

HIGH

SELinux Privilege Elevation

264

CWE

Product Name: OpenSSH

Affected Version From: OpenSSH-SNAP-20070303.tar.gz

Affected Version To: N/A

Patch Exists: Yes

Related CWE: N/A

CPE: N/A

Metasploit: N/A

Other Scripts: N/A

Tags: N/A

CVSS Metrics: N/A

Nuclei References: N/A

Nuclei Metadata: N/A

Platforms Tested: Fedora/RHEL Linux, Windows, Linux, Mac

2008

Debian (maybe other derivates |KUDUBUTUNTU|) OpenSSH Remote -=Authenticated=- SELinux Privilege Elevation

This vulnerability allows an authenticated user to set arbitrary SELinux roles when OpenSSH is configured with --with-selinux. This is done by specifying the role in the username after a forward slash '/'. This is a bug jailed in some distros because of legacy code.

Mitigation:

Upgrade to the latest version of OpenSSH and ensure that the --with-selinux flag is not enabled.

Source

Exploit-DB raw data:

/* Debian (maybe other derivates |KUDUBUTUNTU|) OpenSSH Remote -=Authenticated=- SELinux Privilege Elevation
*** Fedora/RHEL Linux should be tested because it _MAY_ contain the same vulnerability
*** in it's OpenSSH patches in a time slice. Latest OpenSSH should not be vulnerable. Older Debian Releases may.
**** One vulnerable example is "openssh-SNAP-20070303.tar.gz", currently reachable at
****  ftp://ftp.bit.nl/mirror/openssh/openssh-SNAP-20070303.tar.gz
****
*** See the "Diff Patch" by Debian:
*** +		authctxt->role = role ? xstrdup(role) : NULL;
**** Where the role is defined in the username after a forward slash '/'
**** So anyone can set arbritrary SELinux roles, when OpenSSH is configured with --with-selinux - 
**** What is a common configuration nowadays.
**** For the kids:
***** ssh -lusername:[style]/<arbritrary SELinux role> host
***** ssh -p2222 -lusername:/wishedrole 127.0.0.1
**** ':' means [style] -> [[not relevant]] '/'<arbritrary SELinux role> is the specified SELinux role.
**** 
**** This seams to be a bug jailed in some distros because of legacy code.
****
**** 'Exploit' found and delivered by Kingcope.
***//Å½eliteb0yÅ½//
**** CHEERIO ****/
REM blablablaIHAVEPRETTYIDEAHOWSELINUXRUNSWORKSORWHATEVERblablabla

# milw0rm.com [2008-07-17]