Roshan Newa SaranshChauhan Security Flaws in Windows XP
About Windows XPerience • first consumer oriented OS built on Windows NT kernel • first released on 25 October 2001 • Improved GUI, tight integration of application such as IE and Windows Media player, firewall • much vaunted most secured Windows OS so far. • 40 Million SLOC (Source lines of code)
UPnP • protocols that allow devices to connect and communicate seamlessly • dynamically join a network, obtain an IP address, announce its name, convey its capabilities upon request, and learn about the presence and capabilities of other devices • used in XP to detect and integrate with UPNP aware devices by providing a URL for automatic configuration
UPnP Flaw in XP • three separate exploits: • a remote buffer overflow flaw, which can load remote code into an XP system; • Denial of Service (DoS) • Distributed Denial of Service (DDoS) flaws, which can let intruders use zombie XP systems to flood Internet servers with bogus requests
UPnP in XP : Buffer Overflow • The memory registers EAX and ECX are overwritten causing them to contain invalid addresses • svchost.exe process will access an invalid memory address at a 'mov' instruction • The SSDP service also listens on Multicast and Broadcast addresses • Gaining system access to an entire network of XP machines is possible with only one anonymous UDP SSDP attack session
UPnP in XP: DoS and DDoS • UPNP device sends out an advertisement • Attacker: • sends a ,malicious spoofed UDP packet containing an SSDP advertisement • force the XP client to connect back to a specified IP address and pass on a specified HTTP/HTTPS request • specify a CHARGEN (Character Generator) service on a remote machine causing the XP client to connect and get caught in a tight read/malloc loop
UPnP in XP • Deliberate intention by Microsoft for UPnP to work that way. • Microsoft describes the flaw as "unprecedented" and "serious," and the company is providing a wide range of fixes • Microsoft Security Bulletin MS01-054
Escalation of Privilege (EOP) • Permission against verification of identity. • exploiting a bug or design flaw to gain access to resources • result : the application performs actions with more privileges than intended • Elevation of privilege," then, is not a class of attack, as much as it is the process of any attack.
EOP in XP • EOP: Vertical and Horizontal • Identity demonstrated by tokens associated user. • software program obtain privileges • Installation/startup script tells your system what the software needs in order to run • system tracks privileges associated with each user and application • Applications not needing extensive permissions usually run with privileges of the current request. • Installing as administrator have access to more privileges needed
Attacking via EOP in XP • Run code on the victim's machine borrowing the privileges of one of his system-level apps. • find process that is running with higher privileges • Crash it so that you do something that makes it give its privileges to you • interrupt the program as it executes, and makes it run additional code supplied by the attacker • install a set of tools, referred to as a root kit
EOP in XP : Examples • C:\Documents and Settings\All Users\Start Menu\Programs\Startup • Flaw in Network Connection Manager (Microsoft Security Bulletin MS02-042) • Vulnerability in Plug and Play (Microsoft Security Bulletin MS05-055) • Vulnerability in Windows (Microsoft Security Bulletin MS06-075) • Vulnerability in Windows Kernel (Microsoft Security Bulletin MS06-049) • Vulnerability in Internet Information Services (Microsoft Security Bulletin MS08-005)
XP Recovery Console • perform a limited range of tasks using a CLI • enable administrators to recover from situations where Windows does not boot to GUI • Use, copy, rename, or replace files and folders • Enable or disable service or device startup • Repair the boot sector or (MBR) • Create and format partitions on drives
Flaw in XP Recovery Console • Win2k Boot Disc Can Bypass Windows XP Passwords • In Win2k password is mandatory, Under Windows XP, this technique grants the user unrestricted access to the computer • physical access to a PC for a long enough period of time • install keystroke logging software to steal passwords or backdoor programs to grant themselves unrestricted remote access
Flaw in XP Recovery Console • problem is unrelated to a registry feature of XP that allows an Administrator to set up automatic logon when the Recovery • BIOS level password • Encrypted file system • put the PCs behind a locked door or put a lock on the PCs themselves
Remote Code Execution • Feature of network enabled application. • ability to trigger any arbitrary command on the target machine or a target process without physical access to the target system • worst effect a bug can have because it allows an attacker to completely take over the vulnerable process • commonly exploited by malware to run on a computer without the owners consent
Remote Code Execution in XP • Typically triggered by buffer overflow and holes in applications: • help and Support center feature: • remotely execute code on vulnerable systems because of the way the Help and Support Center handles HCP URL validation • triggered by visiting a malicious website or viewing a malicious email message • unregister the HCP protocol to block known attack vectors by deleting from the registry
Remote Code Execution in XP • IGMPv3 • vulnerability exists in the Internet Group Management Protocol Version 3 (IGMPv3) for IPv4 and the Multicast Listener Discovery (MLD) for IPv6 • a remote, unauthenticated attacker, sending specially crafted packets, could run arbitrary code in the security context of SYSTEM • Zipped folders flaw could allow remote code execution • Serious AIM flaw allows remote code execution without user interaction
…change of guard
COMEDY OF ERRORS William Shakespeare
COMEDY OF ERRORS (XP-SP2) Bill Gates
Window’s URI Handling • Windows shell insufficiently handles invalid URIs • Attacker could gain the same user rights as the logged on user • What if the user is administrator? Attacker could take complete control of an affected system
Window’s URI Handling Modus Operandi • Create a specially crafted URI • Provide the URI as input to an application • The app attempts to access the resource referred by the URI • Processing specially crafted URI input could allow arbitrary code to be executed
Remote Desktop DDoS attacks • Could let an attacker remotely crash computers • Affects the Windows Remote Desktop Service • Users experience errors ranging from inability to use certain services to small error messages • Nothing much serious, thankfully… link
Remote Desktop DDoS attacks • A version of the Win32 API - may allow a local user to elevate his privileges • Might allow a remote attacker to execute arbitrary code on this host • Attacker needs to find a way to misuse of Win32 API • Lure a user into visiting a specially crafted web page • Execute active content on a web page
Windows Explorer Vulnerability Remote code execution risk • Windows Explorer provides a GUI for accessing file system • Windows handling of COM objects
Windows Explorer Vulnerability Modus Operandi • Get user to click on a link to a malicious website • User prompted to perform several actions needed to connect to a certain file server • File server causes Windows Explorer to fail and allow code execution • Activated with link in email message
and by the way… • How long do you think you would take to find a bug in your code? • What if your code exceeds millions of lines?
Don’t ask Bill Gates; he took seven years…
SMB Remote Code Execution(2001-2008) • SMB (Server Message Block) • Windows Server service - connects different network resources over a network • File servers • Print servers • Send malicious messages to a Windows machine using Windows Server - attempt to take control of the computer
SMB Remote Code Execution MS blog says: "Public tools, including a Metasploit module, are available to perform this attack." Metasploit is an open-source toolkit used by hackers and security professionals to build attack code
SMB Remote Code Execution Modus Operandi • Victim sent a malicious e-mail message • Message, when opened, would try to connect to a server run by the attacker • Steal network authentication credentials from the victim, used to gain access to the victim's machine. • Attack cannot be made across the firewall, only the machines in your local LAN can exploit this flaw
Worms
Blaster - Win32/Msblast • First reported on August 11, 2003 • Reverse engineered a Microsoft patch • Launched a DDoS attack on windowsupdate.com - MS temporarily shut down the site
Blaster - Win32/Msblast Modus Operandi • Exploits a RPC Distributed Component Object Model (DCOM) vulnerability • Displays messages that Bill Gates might not like… “billy gates why do you make this possible ? Stop making money and fix your software!!” And “I just want to say LOVE YOU SAN!!”
Blaster - Win32/Msblast • Detects internet connection and restarts • Executes a fake batchfile to restarts the system • Registry entry, launched every time Windows starts: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\windows auto update = msblast.exe Image Source : http://en.wikipedia.org/wiki/Image:Windows_XP_Emergency_Shutdown.png
Win32/Sasser • Started spreading on April 30, 2004 • Exploits a Buffer Overflow in LSASS (Local Security Authority Subsystem Service) • Scans IP addresses and connects to victims' computers primarily through TCP port 445 and 139
Win32/Sasser • Adds a file file C:\WIN.LOG or C:\WIN2.LOG on the PCs hard disk • Shutdown timer appears due to the worm crashing LSASS.exe • Can be checked by a firewall
SasserizationEffects of the Sasser Worm • News agency Agence France-Presse (AFP) had all its satellite communications blocked for hours • Delta Air Lines having to cancel several trans-atlantic flights • The British Coastguard had its electronic mapping service disabled for a few hours
…and finally…
