ed0e1e4d44
1979 changes to exploits/shellcodes Couchdb 1.5.0 - 'uuids' Denial of Service Apache CouchDB 1.5.0 - 'uuids' Denial of Service Beyond Remote 2.2.5.3 - Denial of Service (PoC) udisks2 2.8.0 - Denial of Service (PoC) Termite 3.4 - Denial of Service (PoC) SoftX FTP Client 3.3 - Denial of Service (PoC) Silverstripe 2.3.5 - Cross-Site Request Forgery / Open redirection SilverStripe CMS 2.3.5 - Cross-Site Request Forgery / Open Redirection Silverstripe CMS 3.0.2 - Multiple Vulnerabilities SilverStripe CMS 3.0.2 - Multiple Vulnerabilities Silverstripe CMS 2.4 - File Renaming Security Bypass SilverStripe CMS 2.4 - File Renaming Security Bypass Silverstripe CMS 2.4.5 - Multiple Cross-Site Scripting Vulnerabilities SilverStripe CMS 2.4.5 - Multiple Cross-Site Scripting Vulnerabilities Silverstripe CMS 2.4.7 - 'install.php' PHP Code Injection SilverStripe CMS 2.4.7 - 'install.php' PHP Code Injection Silverstripe Pixlr Image Editor - 'upload.php' Arbitrary File Upload SilverStripe CMS Pixlr Image Editor - 'upload.php' Arbitrary File Upload Silverstripe CMS 2.4.x - 'BackURL' Open Redirection SilverStripe CMS 2.4.x - 'BackURL' Open Redirection Silverstripe CMS - 'MemberLoginForm.php' Information Disclosure SilverStripe CMS - 'MemberLoginForm.php' Information Disclosure Silverstripe CMS - Multiple HTML Injection Vulnerabilities SilverStripe CMS - Multiple HTML Injection Vulnerabilities Apache CouchDB 1.7.0 and 2.x before 2.1.1 - Remote Privilege Escalation Apache CouchDB 1.7.0 / 2.x < 2.1.1 - Remote Privilege Escalation Monstra CMS before 3.0.4 - Cross-Site Scripting Monstra CMS < 3.0.4 - Cross-Site Scripting (2) Monstra CMS < 3.0.4 - Cross-Site Scripting Monstra CMS < 3.0.4 - Cross-Site Scripting (1) Navigate CMS 2.8 - Cross-Site Scripting Collectric CMU 1.0 - 'lang' SQL injection Joomla! Component CW Article Attachments 1.0.6 - 'id' SQL Injection LG SuperSign EZ CMS 2.5 - Remote Code Execution MyBB Visual Editor 1.8.18 - Cross-Site Scripting Joomla! Component AMGallery 1.2.3 - 'filter_category_id' SQL Injection Joomla! Component Micro Deal Factory 2.4.0 - 'id' SQL Injection RICOH Aficio MP 301 Printer - Cross-Site Scripting Joomla! Component Auction Factory 4.5.5 - 'filter_order' SQL Injection RICOH MP C6003 Printer - Cross-Site Scripting Linux/ARM - Egghunter (PWN!) + execve(_/bin/sh__ NULL_ NULL) Shellcode (28 Bytes) Linux/ARM - sigaction() Based Egghunter (PWN!) + execve(_/bin/sh__ NULL_ NULL) Shellcode (52 Bytes)
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Source: https://code.google.com/p/google-security-research/issues/detail?id=314
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The private Install.framework has a few helper executables in /System/Library/PrivateFrameworks/Install.framework/Resources,
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one of which is suid root:
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-rwsr-sr-x 1 root wheel 113K Oct 1 2014 runner
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Taking a look at it we can see that it's vending an objective-c Distributed Object :)
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[ https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/DistrObjects/DistrObjects.html ]
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The main function immediately temporarily drops privs doing
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seteuid(getuid()); setegid(getgid());
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then reads line from stdin. It passes this to NSConnection rootProxyForConnectionWithRegisteredName to lookup that
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name in the DO namespace and create a proxy to connect to it via.
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It then allocates an IFInstallRunner which in its init method vends itself using a name made up of its pid, time() and random()
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It then calls the setRunnerConnectionName method on the proxy to tell it the IFInstallRunner's DO name so that whoever
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ran the runner can connect to the IFInstallRunner.
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The IFRunnerMessaging protocol tells us the methods and prototypes of the remote methods we can invoke on the IFInstallRunner.
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Most of the methods begin with a call to processKey which will set the euid back to root if the process can provide a valid admin
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authorization reference from authd (I'm not totally sure how that bit works yet, but it's not important for the bug.) Otherwise the euid
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will remain equal to the uid and the methods (like movePath, touchPath etc) will only run with the privs of the user.
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The methods then mostly end with a call to restoreUIDs which will drop back to euid==uid if we did temporarily regain root privs (with the auth ref.)
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Not all methods we can invoke are like that though...
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IFInstallRunner setExternalAuthorizationRef calls
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seteuid(0);setegid(0);
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to regain root privs without requiring any auth. It then calls AuthorizationCreateFromExternalForm passing the bytes of an NSData we give it.
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If that call doesn't return 0 then the error branch calls syslog with the string: "Fatal error: unable to internalize authorization reference."
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but there's actually nothing fatal, it just returns from the method, whereas the success branch goes on to restore euid and egid, which means
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that if we can get AuthorizationCreateFromExternalForm to fail then we can get the priv dropping-regaining state machine out-of-sync :)
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Getting AuthorizationCreateFromExternalForm to fail is trivial, just provide a malformed auth_ref (like "AAAAAAAAAAAAAAAAAAA" )
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Now the next method we invoke will run with euid 0 even without having the correct auth ref :)
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This PoC first calls setBatonPath to point the baton executable path to a localhost bind-shell then triggers the bug
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and calls runTaskSecurely which will create an NSTask and launch the bind-shell with euid 0 :) We can then just nc to it and get a root shell
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tl;dr:
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the error path in setExternalAuthorizationRef should either be fatal or drop privs!
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Make sure you have the latest xcode installed and run the get_shell.sh script to build and run the PoC.
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Proof of Concept:
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https://github.com/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/38138.zip |