4.0

More documents

Recommendations

Info

172 Web Application Penetration Testing suites or Certificates. Apart from other vulnerabilities discussed in other parts of this guide, a vulnerability exists when the server provides the website both with the HTTP and HTTPS protocols, and permits an attacker to force a victim into using a non-secure channel instead of a secure one. Surf Jacking The Surf Jacking attack [7] was first presented by Sandro Gauci and permits to an attacker to hijack an HTTP session even when the victim’s connection is encrypted using SSL or TLS. The following is a scenario of how the attack can take place: • Victim logs into the secure website at https://somesecuresite/. • The secure site issues a session cookie as the client logs in. • While logged in, the victim opens a new browser window and goes to http:// examplesite/ • An attacker sitting on the same network is able to see the clear text traffic to http://examplesite. • The attacker sends back a “301 Moved Permanently” in response to the clear text traffic to http://examplesite. The response contains the header “Location: http://somesecuresite /”, which makes it appear that examplesite is sending the web browser to somesecuresite. Notice that the URL scheme is HTTP not HTTPS. • The victim’s browser starts a new clear text connection to http://somesecuresite/ and sends an HTTP request containing the cookie in the HTTP header in clear text • The attacker sees this traffic and logs the cookie for later use. To test if a website is vulnerable carry out the following tests: [1] Check if website supports both HTTP and HTTPS protocols [2] Check if cookies do not have the “Secure” flag SSL Strip Some applications supports both HTTP and HTTPS, either for usability or so users can type both addresses and get to the site. Often users go into an HTTPS website from link or a redirect. Typically personal banking sites have a similar configuration with an iframed log in or a form with action attribute over HTTPS but the page under HTTP. An attacker in a privileged position - as described in SSL strip [8] - can intercept traffic when the user is in the http site and manipulate it to get a Man-In-The-Middle attack under HTTPS. An application is vulnerable if it supports both HTTP and HTTPS. Testing via HTTP proxy Inside corporate environments testers can see services that are not directly accessible and they can access them only via HTTP proxy using the CONNECT method [36]. Most of the tools will not work in this scenario because they try to connect to the desired tcp port to start the SSL/TLS handshake. With the help of relaying software such as socat [37] testers can enable those tools for use with services behind an HTTP proxy. Example 8. Testing via HTTP proxy To connect to destined.application.lan:443 via proxy 10.13.37.100:3128 run socat as follows: Then the tester can target all other tools to localhost:9999: $ openssl s_client -connect localhost:9999 All connections to localhost:9999 will be effectively relayed by socat via proxy to destined.application.lan:443. Configuration Review Testing for Weak SSL/TLS Cipher Suites Check the configuration of the web servers that provide https services. If the web application provides other SSL/TLS wrapped services, these should be checked as well. Example 9. Windows Server Check the configuration on a Microsoft Windows Server (2000, 2003 and 2008) using the registry key: $ socat TCP-LISTEN:9999,reuseaddr,fork PROXY:10.13.37.100:destined.application.lan:443,proxyport=3128 HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\ that has some sub-keys including Ciphers, Protocols and KeyExchangeAlgorithms. Example 10: Apache To check the cipher suites and protocols supported by the Apache2 web server, open the ssl.conf file and search for the SSLCipherSuite, SSLProtocol, SSLHonorCipherOrder,SSLInsecureRenegotiation and SSLCompression directives. Testing SSL certificate validity – client and server Examine the validity of the certificates used by the application at both server and client levels. The usage of certificates is primarily at the web server level, however, there may be additional communication paths protected by SSL (for example, towards the DBMS). Testers should check the application architecture to identify all SSL protected channels. Tools • [21][Qualys SSL Labs - SSL Server Test | https://www.ssllabs. com/ssltest/index.html]: internet facing scanner • [27] [Tenable - Nessus Vulnerability Scanner | http://www. tenable.com/products/nessus]: includes some plugins to test different SSL related vulnerabilities, Certificates and the presence of HTTP Basic authentication without SSL. • [32] [TestSSLServer | http://www.bolet.org/TestSSLServer/]: a java scanner - and also windows executable - includes tests for cipher suites, CRIME and BEAST • [33] [sslyze | https://github.com/iSECPartners/sslyze]: is a python script to check vulnerabilities in SSL/TLS.
173 Web Application Penetration Testing • [28] [SSLAudit|https://code.google.com/p/sslaudit/]: a perl script/windows executable scanner which follows Qualys SSL Labs Rating Guide. • [29] [SSLScan | http://sourceforge.net/projects/sslscan/] with [SSL Tests|http://www.pentesterscripting.com/discovery/ ssl_tests]: a SSL Scanner and a wrapper in order to enumerate SSL vulnerabilities. • [31] [nmap|http://nmap.org/]: can be used primary to identify SSL-based services and then to check Certificate and SSL/TLS vulnerabilities. In particular it has some scripts to check [Certificate and SSLv2|http://nmap.org/nsedoc/scripts/ssl-cert.html] and supported [SSL/TLS protocols/ciphers|http://nmap.org/ nsedoc/scripts/ssl-enum-ciphers.html] with an internal rating. • [30] [curl|http://curl.haxx.se/] and [openssl|http://www. openssl.org/]: can be used to query manually SSL/TLS services • [9] [Stunnel|http://www.stunnel.org]: a noteworthy class of SSL clients is that of SSL proxies such as stunnel available at which can be used to allow non-SSL enabled tools to talk to SSL services) • [37] [socat| http://www.dest-unreach.org/socat/]: Multipurpose relay • [38] [testssl.sh| https://testssl.sh/ ] References OWASP Resources • [5] [OWASP Testing Guide - Testing for cookie attributes (OTG- SESS-002)|https://www.owasp.org/index.php/Testing_for_ cookies_attributes_(OTG-SESS-002)] • [4][OWASP Testing Guide - Test Network/Infrastructure Configuration (OTG-CONFIG-001)|https://www.owasp.org/index. php/Test_Network/Infrastructure_Configuration_(OTG-CON- FIG-001)] • [6] [OWASP Testing Guide - Testing for HTTP_Strict_Transport_Security (OTG-CONFIG-007)|https://www.owasp.org/ index.php/Test_HTTP_Strict_Transport_Security_(OTG-CON- FIG-007)] • [2] [OWASP Testing Guide - Testing for Sensitive information sent via unencrypted channels (OTG-CRYPST-003)|https:// www.owasp.org/index.php/Testing_for_Sensitive_information_sent_via_unencrypted_channels_(OTG-CRYPST-003)] • [3] [OWASP Testing Guide - Testing for Credentials Transported over an Encrypted Channel (OTG-AUTHN-001)|https://www. owasp.org/index.php/Testing_for_Credentials_Transported_ over_an_Encrypted_Channel_(OTG-AUTHN-001)] • [22] [OWASP Cheat sheet - Transport Layer Protection|https://www.owasp.org/index.php/Transport_Layer_Protection_Cheat_Sheet] • [23] [OWASP TOP 10 2013 - A6 Sensitive Data Exposure|https://www.owasp.org/index.php/Top_10_2013-A6-Sensitive_Data_Exposure] • [24] [OWASP TOP 10 2010 - A9 Insufficient Transport Layer Protection|https://www.owasp.org/index.php/ Top_10_2010-A9-Insufficient_Transport_Layer_Protection] • [25] [OWASP ASVS 2009 - Verification 10|https://code.google. com/p/owasp-asvs/wiki/Verification_V10] • [26] [OWASP Application Security FAQ - Cryptography/ SSL|https://www.owasp.org/index.php/OWASP_Application_ Security_FAQ#Cryptography.2FSSL] Whitepapers • [1] [RFC5246 - The Transport Layer Security (TLS) Protocol Version 1.2 (Updated by RFC 5746, RFC 5878, RFC 6176)|http:// www.ietf.org/rfc/rfc5246.txt] • [36] [RFC2817 - Upgrading to TLS Within HTTP/1.1|] • [34] [RFC6066 - Transport Layer Security (TLS) Extensions: Extension Definitions|http://www.ietf.org/rfc/rfc6066.txt] • [11] [SSLv2 Protocol Multiple Weaknesses |http://osvdb. org/56387] • [12] [Mitre - TLS Renegotiation MiTM|http://cve.mitre.org/ cgi-bin/cvename.cgi?name=CVE-2009-3555] • [13] [Qualys SSL Labs - TLS Renegotiation DoS|https://community.qualys.com/blogs/securitylabs/2011/10/31/tls-renegotiation-and-denial-of-service-attacks] • [10] [Qualys SSL Labs - SSL/TLS Deployment Best Practices|https://www.ssllabs.com/projects/best-practices/index. html] • [14] [Qualys SSL Labs - SSL Server Rating Guide|https://www. ssllabs.com/projects/rating-guide/index.html] • [20] [Qualys SSL Labs - SSL Threat Model|https://www.ssllabs.com/projects/ssl-threat-model/index.html] • [18] [Qualys SSL Labs - Forward Secrecy|https://community. qualys.com/blogs/securitylabs/2013/06/25/ssl-labs-deploying-forward-secrecy] • [15] [Qualys SSL Labs - RC4 Usage|https://community.qualys. com/blogs/securitylabs/2013/03/19/rc4-in-tls-is-brokennow-what] • [16] [Qualys SSL Labs - BEAST|https://community.qualys. com/blogs/securitylabs/2011/10/17/mitigating-the-beast-attack-on-tls] • [17] [Qualys SSL Labs - CRIME|https://community.qualys. com/blogs/securitylabs/2012/09/14/crime-information-leakage-attack-against-ssltls] • [7] [SurfJacking attack|https://resources.enablesecurity.com/ resources/Surf%20Jacking.pdf] • [8] [SSLStrip attack|http://www.thoughtcrime.org/software/ sslstrip/] • [19] [PCI-DSS v2.0|https://www.pcisecuritystandards.org/ security_standards/documents.php] • [35] [Xiaoyun Wang, Hongbo Yu: How to Break MD5 and Other Hash Functions| http://link.springer.com/chapter/10.1007/11426639_2] Testing for Padding Oracle (OTG-CRYPST-002) Summary A padding oracle is a function of an application which decrypts encrypted data provided by the client, e.g. internal session state stored on the client, and leaks the state of the validity of the padding after decryption. The existence of a padding oracle allows an attacker to decrypt encrypted data and encrypt arbitrary data without knowledge of the key used for these cryptographic operations. This can lead to leakage of sensible data or to privilege escalation vulnerabilities, if integrity of the encrypted data is assumed by the application. Block ciphers encrypt data only in blocks of certain sizes. Block sizes used by common ciphers are 8 and 16 bytes. Data where the size doesn’t match a multiple of the block size of the used cipher has to be padded in a specific manner so the decryptor is able to strip the padding. A commonly used padding scheme is PKCS#7. It fills the remaining bytes with the value of the padding length.
Page 1 and 2:
1 Testing Guide 4.0 Project Leaders
Page 3 and 4:
Testing Guide Foreword - Table of c
Page 5 and 6:
3 Testing Guide Foreword - Table of
Page 7 and 8:
5 Testing Guide Foreword - By Eoin
Page 9 and 10:
7 Testing Guide Frontispiece 1 Test
Page 11 and 12:
9 Testing Guide Introduction 2 The
Page 13 and 14:
11 Testing Guide Introduction vide
Page 15 and 16:
13 Testing Guide Introduction Testi
Page 17 and 18:
15 Testing Guide Introduction laid
Page 19 and 20:
17 Testing Guide Introduction valid
Page 21 and 22:
19 Testing Guide Introduction USER
Page 23 and 24:
21 Testing Guide Introduction ment
Page 25 and 26:
23 Testing Guide Introduction offen
Page 27 and 28:
25 The OWASP Testing Framework sect
Page 29 and 30:
27 Web Application Penetration Test
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
101 Web Application Penetration Tes
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124: 121 Web Application Penetration Tes
Page 173: 171 Web Application Penetration Tes
Page 211 and 212: 209 same code can be applied to ses
Page 213 and 214: 211 Reporting Test ID Lowest versio
Page 215 and 216: 213 Reporting Test ID Business Logi
Page 217 and 218: 215 Appendix kajfghlhfkcocafkcjlajl
Page 219 and 220: 217 Appendix Testing - http:/www.ni
Page 221 and 222: 219 Cross Site Scripting (XSS) For
Page 223 and 224: 221 LDAP Injection For details on L
show all

4.0

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?