Art of InfoJacking - SecNiche Security Labs · POST classification input handling –Forcing the...

Software Confidence. Achieved.

Sunday, April 01, 2012 1

Art of InfoJacking Detecting/Testing Web Network Devices – Hidden Patterns

Aditya K Sood Security Researcher

adi_ks [at] secniche.org | [email protected]

Source Security Conference

15th-16th June 2011, Seattle

© 2011 Cigital Inc. 2 Sunday, April 01, 2012

About Me

Aditya K Sood

─ Founder , SecNiche Security (Research Arena)

● Independent Security Consultant, Researcher and Practitioner

● Worked previously for Armorize, Coseinc and KPMG

● Active Speaker at Security conferences

● Written Content for – ISSA/ISACA/Virus Bulletin/

CrossTalk/HITB/Hakin9/Elsevier NESE|CFS

● LinkedIn : http://www.linkedin.com/in/adityaks

● Website: http://www.secniche.org | Blog: http://secniche.blogspot.com

─ PhD Candidate at Michigan State University


Words

Disclaimer

All vulnerabilities and attacks presented in this presentation were discovered during my

professional avocation with web application penetration testing and research.

This research is different from my ongoing routine work.

All contents of this presentation represent my own beliefs and views and do not, unless

explicitly stated otherwise, represent the beliefs of my current, or any of my previous in that

effect, employers.

All for Education and Development Purposes

Sincere Thanks

Joel Scambray (Managing Principal, Cigital)

Richard J Enbody ( A. Professor, Michigan State University)


Agenda

Disclaimer

Information Gathering Facets

Information Truth

Web Network Devices

HTTP Cloaking

Inside Layer 7 (HTTP) Policy Metrics

Custom HTTP Response Headers

Cookie and IP Session Management

Proxy Protocols

Web Proxy Auto Detection (WPAD)

Proxy Auto Configuration (PAC)

Anonymous Services

Art of Information Gathering

Vulnerable and Bad Design Practices in Network Devices

Conclusion


Information Gathering – Perspectives !


Information Gathering – Truth !


Web Network Devices

Pictures Courtesy – Google Search


HTTP Cloaking

Inside Server Cloaking

─ Bait and switch paradigm

─ General working

– To serve different pages to search engines and generic requests

– Web server is scripted to return original pages to search engines by

fingerprinting search spider requests

– Basically, a stealth process of hiding the reality of web servers

– Thought- cloaking is necessary to protect the meta data. Is it ethical?

─ Is it true server cloaking technique is used by web based security

devices?

– Yes, Web Application Firewalls (WAF’s) use this technique effectively

– Zero visibility

» Internal web servers

» Internal application servers

» Operating systems in use

» Applied patch levels

– Target – to conceal all sensitive information that may result in potential

attack


HTTP Cloaking (Cont..)

Considered as an implicit technique to thwart web attacks – Combining HTTP Cloaking with web net work security devices provides

additional layer of security

– It is required to protect the URL space of the internal web servers

– Looks quite robust from security point of view

─ Applied Techniques

● HTTP response header manipulation and rewriting

– Rewriting the sensitive data information from the headers

– Manipulating the layout of HTTP response headers

– Adding custom headers for traffic management based on user information

● URL translations

– Web Address Translation (WAT) proposed in 2007 by Net continuum

– URL address translation from exterior to interior networks

– Typically, based on DNS namespaces and implicit mapping

– Internal application changes does not impact the external URL scheme

– Web administrators have full access to the user requests and the resultant

URL’s


Facets of HTTP Cloaking

Pictures Courtesy – Google Search


Layer 7 – HTTP Policy Designing

Layer 7 Policy Differentiators

Defining the depth of HTTP request parsing – Forcing the device to read the number of bytes in HTTP request

POST classification input handling – Forcing the device to scrutinize HTTP header or HTTP Body or both

Persistent switching mode – Defines behavior with multiple client requests over the same TCP connection.

– First request/ complete and overwrite /complete and maintain

HTTP request normalization – Enables or disables normalization of URLs in HTTP requests, before parsing

the HTTP request itself.

Explicit farm naming – Explicitly configure the name of the farm with the load that must be taken into

consideration during the DNS resolve phase

Backend port encryption


Layer 7 Content Switching

Effective process of switching traffic – Heavily used by web based network security devices

– Content is switched based on the URL header information

– Sometimes used collaboratively with the WAF’s

Content Switching – How?

● URL header matching criteria

– HTTP response header

– HTTP status codes

– Client IP address

– HTTP versions (HTTP1.0/ HTTP1.1)

– HTTP methods

– URL and URI pathinfo

– Header value

● Load balancing

– Appropriate HTTP handling and redirection

– Algorithms (Round Robin/ Weighted Round Robin / Least Requested)


HTTP Request Normalization

Security Devices and Normalization – WAF’s and IDS/IPS has to perform normalization to incoming HTTP

requests

– Normalization is required to manage the detection/prevention control

mechanism

– Depends on web server compliance in accordance to HTTP RFC

Productivity

● HTTP Requests Fuzzing

– Analyzing HTTP responses by sending invalid HTTP verbs

– Return status code provides a lot of information

– Also depends on the configuration of web server that allows HTTP methods

– WAF’s and IDS/IPS – fuzzing may result in bypass and helps in designing

bypasses

– Examples

– Invalid verbs (POSTTT , GETTT, ROGUE, \r\n\r\n\r\n etc)

– Using encoded separators instead of white characters (%20 \t)

– Encoding (Unicode, double encoding, %, //, %00, etc)


HTTP Cloaking (Example 1)

Response Check 1

HTTP/1.1 200 OK\r\n

Date: Tue, 05 Jul 2007 17:05:18 GMT\r\n

Server: Server\r\n

Vary: Accept-Encoding,User-Agent\r\n

Content-Type: text/html;

charset=ISO-8859-1\r\n

nnCoection: close\r\n

Transfer-Encoding: chunked\r\n

Response Check 2

send: 'GET /?Action=DescribeImages&AWSAccessKeyId=0CZQCKRS3J69PZ6QQQR2&Owner.1 =084307701560&SignatureVersion=1&Version=2007-01- 03&Signature=<signature removed> HTTP/1.1\r\nHost: ec2.amazonaws.com:443\r\nAccept- Encoding: identity\r\n\r\n' reply: 'HTTP/1.1 200 OK\r\n' header: Server: Apache-Coyote/1.1 header: Transfer-Encoding: chunked header: Date: Thu, 15 Feb 2007 17:30:13 GMT

send: 'GET /?Action=ModifyImageAttribute&Attribute=launchPermission&AWSAccessKeyId =0CZQCKRS3J6 9PZ6QQQR2&ImageId=ami-00b95c69&OperationType=add&SignatureVersion=1& Timestamp=2007- 02-15T17%3A30%3A14&UserGroup.1=all&Signature=<signature removed> HTTP/1.1\r\nHost: ec2.amazonaws.com:443\r\nAccept-Encoding: identity\r\n\r\n' reply: 'HTTP/1.1 400 Bad Request\r\n' header: Server: Apache-Coyote/1.1 header: Transfer-Encoding: chunked header:

Date: Thu, 15 Feb 2007 17:30:14 GMT header: nnCoection: close

Citrix NetScaler

(WAF + Load Balancer)



Request /Response Check

GET / HTTP/1.1

Host example.com

User-Agent Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.2.12) Gecko/20101026 Firefox/3.6.12

Accept text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Keep-Alive 115

Connection keep-alive

(Status-Line) HTTP/1.1 301 Moved Permanently

Date Mon, 08 Nov 2010 19:49:23 GMT

Cneonction close

Content-Type httpd/unix-directory

Set-Cookie uu=9mjpm8rn90Duu4CQwFOZbQPyOCTl4V6yoHENgcCxLaHVsZ3h5dQ99JSlTTGlpO4Tw/IehNChDcKgwZ4SkLD98SNSnGEggS3RM4FdkEVkaDIDUknUIRRI9fOEyYXz10uCA9bKIgdm+sIHNgpXl6YLh+ChPhIREU2wQKD9obDCvgGQ0Y3BwNGN8eNSvhGz0h6ypaRIUuPyHvWQ8paioPEtkaDRnSGAwr4RsLFNwcDRnSGDwr4Rs9IesqPUWCLgwh6yoME9ocDRnSGT4r4Rs9IesqPyHvLjom6Co=;expires=Thu, 30 Dec 2037 00:00:00 GMT;path=/;domain=.imdb.com

Set-Cookie session-id=284-9245763-9527093;path=/;domain=.imdb.com

Set-Cookie session-id-time=1289332163;path=/;domain=.imdb.com

Vary Accept-Encoding,User-Agent

Content-Encoding gzip

P3P policyref="http://i.imdb.com/images/p3p.xml",CP="CAO DSP LAW CUR ADM IVAo IVDo CONo OTPo OUR DELi PUBi OTRi BUS PHY ONL UNI PUR FIN COM NAV INT DEM CNT STA HEA PRE LOC GOV OTC "

Content-Length 20

Citrix NetScaler




Response Check 1 HTTP/1.0 404 Not Found\r\n Xontent-Length: \r\n Server: thttpd/2.25b 29dec2003\r\n Content-Type: text/html; charset=iso-8859-1\r\n Last-Modified: Tue, 05 Jul 2010 17:01:12 GMT\r\n Accept-Ranges: bytes\r\n Cache-Control: no-cache, no-store\r\n Date: Tue, 05 Jun 2010 17:01:12 GMT\r\n Content-Length: 329\r\n Connection: close\r\n HTTP/1.0 302 Moved Temporarily Age: 0 Date: Thu, 11 Mar 2010 12:01:55 GMT Xontent-Length: Connection: Close Via: NS-CACHE-7.0: 11 ETag: "KXIPDABNAPPNNTZS" Server: Microsoft-IIS/6.0 X-Powered-By: ASP.NET X-Powered-By: PHP/5.1.6 Location: http://216.99.132.20/smb/index.php Content-type: text/html Xontent-Length: \r\n:”

Citrix NetScaler





─ Web security devices add its own custom response headers

─ General working

– WAF’s usually adds HTTP response headers

– All the HTTP traffic is routed through the intermediate security device

– Basically, VIA: and Cache: response headers are added

– Primarily, there is no need to request web server every time if an updated

copy of web site is present in the cache

– Via: header supports the fact that traffic is handled by another device in the

network which can make changes in the inbound and outbound HTTP traffic


Custom HRH (Example)

Response Headers

HTTP/1.0 200 OK Date: Wed, 25 Aug 2010 08:45:45 GMT Content-Type: text/html; charset=utf-8 Transfer-Encoding: chunked Connection: keep-alive Vary: Accept-Encoding Last-Modified: Wed, 25 Aug 2010 08:45:46 GMT X-BinarySEC-Via: frontal2.re.saas.example.com

HTTP/1.0 301 Moved Permanently Content-length: 0 Content-language: fr X-binarysec-cache: saas.example.com Connection: keep-alive Location: http://www.binarysec.fr/cms/index.html Date: Tue, 24 Nov 2009 22:49:01 GMT Content-type: text/html

Content-Type: text/html; charset=utf-8 Transfer-Encoding: chunked Connection: keep-alive Vary: Accept-Encoding Last-Modified: Wed, 25 Aug 2010 08:45:46 GMT X-BinarySEC-Via: frontal2.re.saas.example.com

BinarySec Device


Cookie and IP Session Management

Custom HTTP Response Header (Set-Cookie)

─ Web security devices add its own Set-Cookie response header

– Adding Security to existent cookie (Web Server)

– HTTP Web security devices manages sessions using self driven cookies

– Effective way to manage sessions with intermediate layer of working

– Use internal IP addresses to generate sessions (BIG IP Devices)

─ WAF’. Do they play around with cookie?

● Cookie Encryption (configuration specific)

– Encrypting cookies before sending it to client. Hard to interpret.

– Possible protecting the integrity of the cookies

● Cookie Signing (configuration specific)

– Adding digital signature as second line of defense to existent cookie

– If tampered, digital signature wont be verified in general

– Simple and direct detection mechanisms

– Example: Barracuda Web Application Firewalls does this.


CSM (Example 1)

Response Check (It uses Set_Cookie with “Barracuda” name parameter) HTTP/1.0 500 Internal Server Error Date: Thu, 11 Nov 2010 05:52:54 GMT Server: Microsoft-IIS/6.0 X-Powered-By: ASP.NET X-AspNet-Version: 2.0.50727 Cache-Control: private Content-Type: text/html; charset=utf-8 Content-Length: 5145 Set-Cookie: BNI__BARRACUDA_LB_COOKIE=df0fa8c000005000; Path=/; Max-age=1020 HTTP/1.0 400 Bad Request Content-Type: text/html Date: Thu, 11 Nov 2010 05:02:23 GMT Connection: close Content-Length: 39 Set-Cookie: BARRACUDA_LB_COOKIE=192.168.155.11_80; path=/ HTTP/1.0 200 OK Date: Thu, 11 Nov 2010 10:29:51 GMT Server: BarracudaServer.com (Windows) Connection: Keep-Alive Content-Type: text/html Cache-Control: No-Cache Transfer-Encoding: chunked Set-Cookie: BarracudaDrive=3.2.1; expires=Wed, 07 Sep 2011 10:29:51 GMT

Barracuda WAF


CSM (Example 2)

Request / Response (GEO Location Based Session Management)

(Request-Line) GET / HTTP/1.1

Host www.example.net

User-Agent Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.2.12) Gecko/20101026 Firefox/3.6.12

Accept text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Accept-Language en-us,en;q=0.5

Accept-Encoding gzip,deflate

Accept-Charset ISO-8859-1,utf-8;q=0.7,*;q=0.7

Keep-Alive 115


(Status-Line) HTTP/1.1 200 OK

Accept-Ranges bytes

Content-Type text/html; charset=UTF-8

Date Mon, 08 Nov 2010 18:48:02 GMT


Set-Cookie rl-sticky-key=b159fd3052f1f60eea47e0dc56d57d62; path=/; expires=Mon, 08 Nov 2010

19:35:22 GMT

Set-Cookie

CT_Akamai=georegion=264,country_code=US,region_code=MI,city=EASTLANSING,dma=551,msa=4

040,areacode=517,county=INGHAM,fips=26065,lat=42.7369,long=-84.4838,timezone=EST,zip=48823-

48826,continent=NA,throughput=vhigh,bw=1000,asnum=237,location_id=0; path=/;

domain=example.net

Juniper Sec Device


CSM and IPSM ( Example 3)

Request / Response

E:\audit>nc example.com 80

GET / HTTP/1.1

HOST:example.com

HTTP/1.1 302 Object moved

Server: Microsoft-IIS/5.0

Date: Mon, 08 Nov 2010 17:41:56 GMT

X-Powered-By: ASP.NET

Location: http://www.example.com/us/index.asp

Content-Length: 159

Content-Type: text/html

Set-Cookie: ASPSESSIONIDCCCCSBAA=AHLDLDDANEKJOOPHGOHAAKBA; path=/

Cache-control: private

Set-Cookie: http.pool=167880896.20480.0000; path=/

<head><title>Object moved</title></head>

<body><h1>Object Moved</h1>This object may be found <a

HREF="http://www.example.com/us/index.asp">here</a>.</body>

Big IP Sec Device


CSM and IPSM ( Example 3 Cont…..)

Request / Response

E:\audit>nc example.com 80

GET / HTTP/1.1

HOST:example.com

HTTP/1.1 302 Object moved

Set-Cookie: http.pool=167880896.20480.0000; path=/

Converting to Binary: Binary ( cookie ) Part == 00001010000000011010100011000000

Converting to blocks of 4

00001010

00000001

10101000

11000000

00001010 10

00000001 1

10101000 168

11000000 192

Big IP Sec Device

192.168.1.10


Web Proxy Auto Detection Protocol (WPAD)

Inside WPAD – To detect network proxy automatically

– Protocol based on DHCPINFORM query.

– DHCP based , No DNS. Query is sent through URL

– Configuration entries are present in wpad.dat file

– FindProxyForURL () function is used



Information Driven – Access to wpad.dat leverages lot of critical information

– Becomes easy to map proxy servers and internal network



Information Driven – Beneficial in penetration testing


Proxy Auto Config (PAC)

Inside PAC – Indicates browser to find proxy t( manual implementation)

– FindProxyForURL () function is used


Proxy Auto Config (PAC)

Information Driven


Anonymous Access and Exploitation

Anonymous Access

─ General working

– Some network based security devices allows anonymous access

– To what extent we can exploit the scenario?

– Tactical exploitation and robust techniques are required

– Typically protocol that falls under this is {FTP} as an example



Is that all ?



Is that all ? NO !


Case Study – Synology Diskstation Manager

Is that all ? NO ! FTP Console – Default Buffer Tactic

Determining the number of characters that are acceptable

FTP Protocol

Username – Another generic input point

Password – Another input point



Is that all ? So what ! FTP Console – Using it as an entry point to conduct XSS

Exploiting the vulnerable log module at the backend

Remote code execution using CRSF payload injected through FTP console

Advisory : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3684



Pwned !

Advisory : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3684


HTTP Web Server – Network Devices

HTTP Web Server Types and Usage Listed web servers are used effectively in network based devices

Comparative study of the acceptable HTTP verbs


The Culprit – CGI Implementation

Implementation of CGI enabled interfaces

─ Web security devices uses CGI interface for HTTP functionality

─ Point of command injection. Hidden services execution

─ Unauthorized access and implicit restriction bypasses

─ Examples ( never ending ………)

– /cgi-bin/filemanager/filemanager.cgi?folder=/home/httpd/cgi-

bin/filemanager/share&lang=eng [NAS Device]

– /cgi-bin/password.cgi

– /cgi/maker/unittest.cgi?action=

– /cgi/maker/tools.cgi?command=

– /control/click.cgi?list | /img/image.cgi?next_file=main_fs.htm

– /control/rotorcgi?help

– /en/help.cgi?ID=25 | /main_activex.cgi

– /cgi-bin/wg_login-act.cgi

– /CgiStart?page=Login&Language=0

– /cgi/b/users/usrpage/?nm=1

– /cgi-bin/csi_login-act.cgi


Bad Design or Ignorance !!


Binary Controls and Decompilation

Binary Authentication Controls

─ Bad practice in authentication process

─ Usage of [0|1] and [Yes|No] in the authentication modules

─ Verifying authentication information in URL’s

─ http://www.example.com/auth.php?authenticated=YES|NO

Decompiling Java Applets (JAR Files)

─ Very effective process in detecting and finding information

─ Devices using Java applets must be decompiled

─ Leverages lot of information

─ Hard coded passwords ; Reflected information about sessions

─ Understanding about the login algorithm and specific details


Encryption Issues in Binary Data


Information Patterns – Never Ending


Conclusion


Questions and Gratitude

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