27 August 2010

Vulnerabilities

Posts relating to the category tag "vulnerabilities" are listed below.

27 August 2010

Automated Attack Responses by Web Applications

I have been exploring further the possible response actions an application might make once it has detected a suspected or actual attack, as a contribution to the OWASP AppSensor project. There is now a draft document describing response actions, discussed and announced last week.

Partial image of Table 3 from the new draft document 'AppSensor - Response Actions v0.5' showing some OWASP AppSensor Response Action classifications

The draft document AppSensor - Response Actions describes thirteen response actions, provides examples of each, and discusses how they might be categorised in order to help with selection of appropriate responses.

It is still a working document. If you have any suggestions or comments on the draft document, please send them to the AppSensor project's mailing list, or perhaps add them below. In particular, I'd like to discuss whether there are any other responses which aren't covered by the ones already included.

There is additional background information and links relating to web application intrusion detection and the OWASP AppSensor project in my posts about presentations in Newcastle and London, but I hope to present again later in the year.

Posted on: 27 August 2010 at 08:52 hrs

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10 August 2010

Phishing and Pharming Protection - Theory and Reality

The UK Centre for the Protection of National Infrastructure (CPNI) have published new guidance on understanding and managing the risks from phishing and pharming.

Some of the text from the Centre for the Protection of National Infrastructure (CPNI) infosec briefing on Phishing and Pharming showing the words 'SSL and TLS are not foolproof: it can be complex for users to interpret information about certificates; there have been technical attacks against the technology; and valid websites using SSL or TLS can be compromised and used for malicious ends. Ultimately, SSL and TLS are a form of electronic identity, and as with all identity schemes can be subject to identity fraud. Nonetheless, SSL and TLS is an essential tool in the fight against phishing and pharming. Heading: Cryptographic signing of digital communication. Similar to the use of SSL and TLS, cryptographic certificates can be used to prove the identity of the sender of an email. Using appropriate software, individuals or complete organisations can be issued with a certificate which they then use to digitally

Whilst most readers of this blog won't work on projects considered part of the national infrastructure, that doesn't mean you should ignore good, free advice.

The CPNI document discusses the threats and impacts (on employees, customers, clients and citizens), the modes of attack and possible countermeasures. I'm pleased to see that countermeasures to reduce the likelihood of successful attacks include both technical and cultural measures. Measures to mitigate the effects of successful attacks are also discussed.

Although some of the document is necessarily technical in places, the case studies in Appendix C should make sense to everyone. Remember, this is about business risk, not technical risk. The "I don't understand technical things" argument does not stand up.

Of course, assessing and implementing information security policies and controls is hardly ever simple or quick. But with the government's aim to reduce the number of different web sites this process may be a little easier. It's good to see such guidance, especially when the Central Office of Information (COI) has to date avoided the subject of security in its own web standards and guidelines. In view of the perception that the government isn't keeping up with threats (for example see the response to the petition to upgrade away from Internet Explorer 6), how are the CPNI phishing and pharming countermeasures being implemented by the government?

Knowledge about the degree to which the cultural countermeasures have been adopted within the government sector cannot be adequately measured from outside, and it would be good to see these included in work performed by the National Audit Office. Similarly most of the technical countermeasures would require privileged access to government networks (and permission!). However "use of SSL and TLS" and "signing of digital communications" should be easily observable, without doing any testing, from the outside world.

These two measures have security benefits beyond protection against phishing and pharming. They can assist citizens wanting to verify the identity of, and rely on the integrity of the information they see on what looks like a government web site, or receive in an official-looking email or other form of correspondence, perhaps during a national emergency. These types of event can attract themed phishing attacks for example. I haven't received any official government electronic communications recently apart from reminders from HMRC about tax deadlines and the like, so can't comment on how the sender and data integrity is verified. The tax reminders don't contain any sensitive data, and occur when there are known forthcoming business events or relate to actions undertaken by myself, so correctly don't need the same degree of verification.

But anyone can visit a web site, so what about those? Well, the CPNI web site appears to also be available over SSL/TLS as we'd expect. But, looking at https://www.direct.gov.uk using SSL (now more correctly called transport layer security, TLS) in the Chrome web browser, I was a bit surprised to see:

Screen capture of a web browser showing what is displayed when the website www.hmg.gov.uk is requested over SSL/TLS - it reads 'This is probably not the site that you are looking for! You attempted to reach www.direct.gov.uk, but instead you actually reached a server identifying itself as a248.e.akamai.net. This may be caused by a misconfiguration on the server or by something more serious. An attacker on your network could be trying to get you to visit a fake (and potentially harmful) version of www.direct.gov.uk. You should not proceed.'.

and this is the same for the prime minister's web site at https://www.number10.gov.uk/. Another possible primary governmental address is https://www.hmg.gov.uk which gives:

Screen capture of a web browser showing what is displayed when the website www.hmg.gov.uk is requested over SSL/TLS - it reads 'SSL connection error.  Unable to make a secure connection to the server. This may be a problem with the server or it may be requiring a client authentication certificate that you don't have.  More information on this error - Below is the original error message - Error 107 (net::ERR_SSL_PROTOCOL_ERROR): SSL protocol error.'

Maybe these have been deemed to be acceptable risks. But let's hope the other recommended countermeasures have been implemented.

Posted on: 10 August 2010 at 08:45 hrs

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03 August 2010

Real World Enterprise Application Security Programmes

This year I have mentioned web application security programmes, how software vulnerability testing recommended risk-based, application security programmes and generalised results from a survey about web application security programs.

Photograph of a circular gauge labelled 'synchronisation meter' with a pointer sitting between 'slow' and 'fast' marked on the face, from the London Transport Museum in Covent Garden

But what are enterprises doing in real life and what are the issues? During the second day of OWASP AppSec Research 2010, Michael Craigue of Dell presented on Secure Application Development for the Enterprise: Practical, Real-World Tips. Although I missed it, people who did attend this track were enthusiastic about it and the video recording has now been published. I watched it last weekend.

Michael described Dell's 10-strong Global Information Security Services group and how it works with 3,000-5,000 developers in internal teams and how their appsec work is built on a published and maintained secure application development standard. Some of the problems encountered at Dell were platform diversity, security expert retention, the need to develop self-help documentation for the low and medium risk projects, lack of good metrics around security awareness training, high overhead of conventional threat modelling and the need to build security into the development lifecyle slowly, and in a business-focused manner.

At Dell, the project risk is calculated from ten factors including data classification, compliance requirements, whether it is externally facing, and the security knowledge of the development team. Interestingly, in the final questions from the audience, Michael mentioned Dell are using Open SAMM to identify gaps, measure how well their security programme is performing and to focus improvement efforts. Even projects that the group does not get involved with directly, are subject to quality checks and audit such as using Control Self Assessments (CSAs), which look for the artifacts required in the self-help documentation, even for low-risk applications.

There is another description of how software assurance practices at Ford in 2009, and recently published on US DHS's best practices web site Build Security In. The Ford programme is quite different. Every application security programme is unique because every organisation's culture, application and acceptance of risk is different.

What is yours like?

Posted on: 03 August 2010 at 09:00 hrs

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27 July 2010

When is a Vulnerability not a Vulnerability?

Until this week, I had thought this question would be answered by checking the vulnerability could be exploited and by determining whether there was any technical or business impact.

But I have just finished reading the Summer 2010 edition of Information Security Now, the quarterly magazine of the BCS Security Forum, incorporating the Information Security Specialist Group. One of the articles forced me to stop and think.

The article titled "Attack Spotting" describes the motivation for modern attackers and in particular attacks on application software. But the author introduces the idea of "non-vulnerability attacks". Just what might they be?

Non-vulnerability based threats aim to exploit weaknesses in server applications that cannot be defined as vulnerabilities.

I was even more confused. I thought a vulnerability was any weakness that could be exploited by a threat (and a similar definition). The article's author goes on to describe that in "traditional vulnerability-based attacks", there is always the possibility of creating a signature to block the attack or of developing a patch for the application. In "non-vulnerability-based attacks" the author says there is no malicious payload and therefore it is not possible to create an attack signature or patch. The author helpfully provides three examples of non-vulnerability attacks:

  • Brute force attack on authentication
  • Web application vulnerability scanning
  • Service flooding which exhaust server resources

No, no, no! These are all attacks against real vulnerabilities. These three are listed in Common Weakness Enumeration (CWE) (e.g. CWE-307, CWE-200 and CWE-410) and real examples are listed in Common Vulnerabilities and Exposures (CVE). The examples also fall into categories in the Web Application Security Consortium 's Threat Classification.

These attacks go unnoticed by existing protection technologies and can result in information theft, fraud activities and service disruption.

I have to disagree that these attack methods are new, and that they are not being detected. I may have misunderstood the article, but I believe there is plenty of guidance on building applications securely, security verification and for testing for these types of flaws. I also disagree with the article author's suggestion that the answer lies with expert systems to perform network behavioural analysis (NBA). Why bother? The application already knows right from wrong and doesn't need to guess. Implement application-based intrusion detection and prevention, on top of secure code, and benefit from very low false positives. At least, that's my view.

So, perhaps if it depends on your viewpoint. Maybe some traditional security folk see this other stuff as black magic? I hope not.

Posted on: 27 July 2010 at 09:29 hrs

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09 July 2010

Application Intrusion Detection

Fed up with false positives when trying to detect malicious users with network intrusion detection systems (IDS)? Application intrusion detection is the way to go.

Photograph of a 9ft2in tall fabricated steel robotic sculpture on Clerkenwell Road during Clerkenwell Design Week 2010 - 'Bowser' - created by the Mechanical Alchemist http://mechanical-alchemist.com/

Like an advanced robot, applications can build in security protection, detection and response.

Next Thursday 15th July 2010, I will be presenting "Real Time Application Attack Detection and Response" at the next OWASP meeting in London. Like all OWASP chapter meetings, the event is free but prior registration is required.

I will talk about how advanced attackers probe and try to exploit applications, how some common defences against these attacks are of no use, and why we need to use protection that:

  • understands the application
  • understands normal vs. suspicious use
  • can identify and shut down attackers in real time.

Is this possible? Yes. AppSensor specifies how application-based detection points can be used to stop attackers. I will also describe how project leader Michael Coates has demonstrated how real web sites can deploy such measures in practice to protect an application against automated scanners, advanced attackers and build in protection against application worms.

Arrive from 17:30 hrs since the talks start promptly at 18:00. Hope to see you there.

Posted on: 09 July 2010 at 10:50 hrs

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02 July 2010

Web Site Security Basics for SMEs

Sometimes when I'm out socially and people ask what I do, the conversation progresses to concerns about their own web site. They may have a hobby site, run a micro-business or be a manager or director of a small and medium-sized enterprise (SME)—there's all sorts of great entrepreneurial activity going on.

It is very common for SMEs not to have much time or budget for information security, and the available information can be poor or inappropriate (ISSA-UK, under the guidance of their Director of Research David Lacey, is trying to improve this). But what can SMEs do about their web presence—and it is very unusual not to have a web site, whatever the size of business.

Photograph of a waste skip at the side of St John Street in Clerkenwell, London, UK, with the company's website address written boldly across it

Last week I was asked "Is using <company> okay for taking online payments?" and then "what else should I be doing?". Remember we are discussing protection of the SME's own web site, not protecting its employees from using other sites. If I had no information about the business or any existing web security issues, this is what I recommend checking and doing before anything else:

  • Obtain regular backup copies of all data that changes (e.g. databases, logs, uploaded files) and store these securely somewhere other than the host servers. This may typically be daily, but the frequency should be selected based on how often data changes and how much data the SME might be prepared to lose in the event of total server failure.
    • check backup data can read and restored periodically
    • don't forget to securely delete data from old backups when they are no longer required
  • Use a network firewall in front of the web site to limit public (unauthenticated user) access to those ports necessary to access the web site. If other services are required remotely, use the firewall to limit from where (e.g. IP addresses) these can be used.
    • keep a record of the firewall configuration up-to-date
    • limit who can make changes to the firewall
  • Ensure the host servers are fully patched (e.g. operating system, services, applications and supporting code), check all providers for software updates regularly and allow time for installing these.
    • remove or disable all unnecessary services and other software
    • delete old, unused and backup files from the host servers
  • Identify all accounts (log in credentials) that provide server access (not just normal web page access), such as used for transferring files, accessing administrative interfaces (e.g. CMS admin, database and server management/configuration control panels) and using remote desktop. Change the passwords. Keep a record of who has access and remove accounts that are no longer required and enable logging for all access using these accounts.
    • restrict what each account can do as much as possible
    • add restrictions to the use of these accounts (e.g. limit access by IP address, require written approval for use, keep account disabled by default)
  • Check that every agreement with third parties that are required to operate the web site are in the organisation's own name. These may include the registration of domain names, SSL certificates, hosting contracts, monitoring services, data feeds, affiliate marketing agreements and service providers such as for address look-up, credit checks and making online payments.
    • ensure the third parties have the organisation's official contact details, and not those of an employee or of the site's developers
    • make note of any renewal dates
  • Obtain a copy of everything required for the web site including scripts, static files, configuration settings, source code, account details and encryption keys. Keep this updated with changes as they are made.
    • verify who legally owns the source code, designs, database, photographs, etc.
    • check what other licences affect the web site (e.g. use of open source and proprietary software libraries, database use limitations).

Do what you can, when you can. Once those are done, then:

  • Verify the web site and all its components (e.g. web widgets and other third party code/content) does not include common web application vulnerabilities that can be exploited by attackers (e.g. SQL injection, cross-site scripting).
  • Check what obligations the organisation is under to protect business and other people's data such as the Data Protection Act, guidance from regulators, trade organisation rules, agreements with customers and other contracts (e.g. PCI DSS via the acquiring bank).
    • impose security standards and obligations on suppliers and partner organisations
    • keep an eye open for changes to business processes that affect data
  • Document (even just some short notes) the steps to rebuild the web site somewhere else, and to transfer all the data and business processes to the new site.
    • include configuration details and information about third-party services required
    • think about what else will need to be done if the web site is unavailable (does it matter, if so what exactly is important?)
  • Provide information to the web site's users how to help protect themselves and their data.
    • point them to relevant help such as from GetSafeOnline, CardWatch and Think U Know
    • provide easy methods for them to contact the organisation if they think there is a security or privacy problem
  • Monitor web site usage behaviour (e.g. click-through rate, session duration, shopping cart abandonment rate, conversion rate), performance (e.g. uptime, response times) and reputation (e.g. malware, phishing, suspicious applications, malicious links) to gather trend data and identify unusual activity.
    • web server logs are a start, but customised logging is better
    • use reputable online tools (some of which are free) to help.

That's just the basics. So, what would be next for an SME? If the web site is a significant sales/engagement channel, the organisation has multiple web sites, is in a more regulated sector or one that is targetted particularly by criminals (e.g. gaming, betting and financial), takes payments or does other electronic commerce, allows users to add their own content or processes data for someone else, the above is just the start. Those SMEs probably need to be more proactive.

This helps to protect the SME's business information, but also helps to protect the web site users and their information. After all, the users are existing and potential customers, clients and citizens.

Oh, the best response I had to someone when I was explaining my work: "You're an anti-hacker than?". Well, I suppose so, but it's not quite how I'd describe it.

Any comments or suggestions?

Posted on: 02 July 2010 at 08:18 hrs

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30 April 2010

Software Assurance Labelling

An article about the upcoming new regime for the classification and labelling of chemicals reminded me to write about software assurance (i.e. software security) labelling (and since web sites are software). From 1 December 2010, the UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS) comes into force, implemented in Europe by the Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures (CLP), amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006.

Four type of warning labels - a skull and crossbones indicating acute toxicity, an exclamation mark indicating other harm, an exploding bomb indicating an explosive substance and the profile of a human's head and shoulders indicating hazardous to human health

CLP implications and guidelines are explained by the UK Health and Safety Executive (HSE) but are defined fully in the UN's documentation. The headline chemical labelling indicates the potential damage/harm that can occur, rather than the content/properties of the agent. I like this "impact" approach. Nutritional labelling on the other hand generally tends to focus on ingredients and their properties, but some food labelling is also beginning to attempt to classify low/medium/high fat/saturates/sugars/salt levels, which is more akin to the impact approach.

Jeff Williams (CEO of Aspect Security and Chair of OWASP Foundation) proposed a Software Facts label five years ago at OWASP Appsec Europe. This would be similar to appliance energy usage labels, food nutrition facts label, material safety data sheets or laser safety classes. That idea was taken up by NIST and the Software Assurance Consortium (SwAC) to develop another proposal.

Comment here and here around the same time in 2005 describes some of the challenges. Indeed many more aspects of the software development lifecycle impact upon the creation of secure software. But simplicity is needed in the presentation of such information—perhaps some high-level impact related indicators augmented by the more detailed information for different audiences (e.g. users, operators, administrators, system achitects). SwAC's version seems to be somewhat aimed at software development teams, instead of people in end user organisations, especially those involved with procurement decisions. Whilst some people will want to know the data behind a classification, most businesses and consumers will need something more akin to the CLP headline labels relating to business (or personal) impact as a starting point for their decisions.

  • How dangerous is this software?
  • How reliable is it?
  • How does it affect privacy?
  • How does the IT environment affect these?
  • How are these affected by changing the default settings?

This a big challenge. Just specifying the privacy practices for a web site can be complex. ENISA's Common Assurance Maturity Model (CAMM) project is trying to define how cloud service providers can be compared to allow users to make informed decisions about the risks. Perhaps that project will develop into some form of labelling scheme, or at least provide ways for typical consumers of the services to determine their own risks as simply as possible.

I don't know the status of the SwAC project but will now make the effort to find out.

Posted on: 30 April 2010 at 08:49 hrs

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27 April 2010

Internet Security Threat Report

Last week, Symantec published its latest Internet Security Threat Report.

Partial image of the cover from Symantec's report 'Global Internet Security Threat Report, Volume XV, April 2010 - Trends for 2009'

The 95-page report describes Symantec's methodology, findings and recommendations about internet security threats to businesses and individuals. It describes the financial and other losses possible such as damage to reputation and data theft. There is a strong focus on protecting confidentiality and less about how internet threats affect the integrity of data and availability of information systems and business processes.

In the two chapters on Vulnerabilities and Malicious Code Trends, the importance of publicly accessible services (web, mail and FTP) and vulnerabilities in web browsers and web browser plugins in the malware ecosystem are highlighted and recommendations for protecting these servers are provided. The top Web-based attack in 2009 was associated with malicious PDF activity, which accounted for 49 percent of the total.

The chapter on Phishing, Underground Economy Servers, and Spam Trends provides a good insight into how your users may be targetted by third parties hoping to lure them into visiting other web sites. the report makes the important point that "the use of brand(s) in phishing activity can significantly undermine consumer confidence in its reputation". The financial sector continues to be the primary target for phishing attacks, but all types of organisation can be targetted.

Appendix A describes some best practices that businesses (enterprises) and consumers should follow to reduce the risk from internet threats. Many of these relate to using electronic mail and browsing web sites. The slightly more web application related recommendations include employ defense-in-depth strategies, administrators should limit privileges on systems for users, turn off and remove services that are not needed for normal company network operations, test security regularly to ensure that adequate controls are in place, educate management on security budgeting needs, administrators should update antivirus definitions regularly, always keep patch levels up to date, enforce an effective password policy and ensure that emergency response procedures are in place.

A shorter executive summary of the report is also available.

Posted on: 27 April 2010 at 09:15 hrs

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02 April 2010

When a Bit of Security Forethought Would Go A Long Way

Thinking of creating a mobile phone application for your business? A major privacy failure with an iPhone application has been reported on the Zero Day blog and is a useful case study.

All iPhone apps have to be approved by Apple to "protect consumer privacy, safeguard children from inappropriate content, and avoid applications that degrade the core experience of the iPhone". But the application Quip from Addy Mobile Inc provides provided unlimited photo texting with the slogan "Why pay more for MMS? Don't you pay enough for your iPhone already?". Well, many of the application's users are paying for it now.

It seems the images (typically photos) were stored on a publicly-accessible web site, with the only access "control" being a random directory (folder) name five characters long—something that is easily iterated through to find photos and breach their customers' privacy. What makes it worse is that many of these messages and images were also turning up in public search engine results leaking sensitive information.

Partial screen capture from Google showing the search results for the query 'site:site:quiptxt.com' that include links and snippets from what were meant to be private messages

I was unable to find any privacy notice or privacy policy from the company:

Partial screen capture from Google showing no search results for the query 'site:site:quiptxt.com privacy'

The cached search results indicate the images are being stored using Amazon Web Services (AWS) S3. This is not a cloud computing specific issue. It could just as well be on a web site hosted by the company itself. The Quip web site (http://www.quiptxt.com), Quip message site (http://www.quiptxt.com) and Quip S3 image repository (http://quipimg.s3.amazonaws.com) are all currently offline. The comany issued a statement via Reddit. As the Zero Day blog says, these vulnerabilities would have been trivial to fix and protect the confidentiality of users' message text and photos. Using any of common sense, threat modelling, risk assessment or security verification should have identified the problems. I'm sure lawyers in the US will be circling. Since Apple approved the application, let's hope they are ready in case the lawyers knock on their door as well.

Addy Mobile Inc may itself be unavailable soon.

Posted on: 02 April 2010 at 11:04 hrs

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01 April 2010

Website Hacked or Just Testing?

Today I was looking around for UK energy providers, and came across this home page from one of the major suppliers:

Partial screen capture of an energy supplier's home page with the phrase 'hello test' amongst some 'find out more' entries

Can you see what's wrong? I don't think "hello test" should be there. It's not humorous enough to be an April Fool's Day joke, and the page footer suggests the text may have been there for a couple of weeks:

Partial screen capture of the footer from the above energy supplier's home page with the date stamp 'Site last updated 18/03/10 15:00:00'

I've mentioned previously test and old pages being found by site searches, but having test content on a PLC's home page is fairly bad. What will potential new customers think? If this appeared in a company's printed brochure, would heads roll?

Was the web site hacked or was it just some poorly thought-out testing? I suspect a hacker might have added something a little bit more malicious than 'hello test' so the implication is the content was added by an authorised person. I'm worried that the live site is being used as a test platform and that content can be added without review or approval. Also, why has site monitoring not picked up on this change?

I tried to "email" the company concerned but their web form insisted I had to be a customer, so I rang a telephone number instead which again asked for an account number. I eventually got through to someone and explained the problem. It's been "passed to the IT Department". Really? Not PR or Marketing?

Don't make it difficult for people with good intentions to tell you about concerns, possible security incidents or phishing emails—help them to do it easily and quickly. You'll benefit. Why do you think food manufacturers try to encourage you to contact them about complaints, rather than leaving you to speak with your local trading standards department?

Update 14:30 hrs: No change yet—let's hope it wasn't a hacker and digital forensics are beginning.

Update 16:40 hrs: The text has been removed.

Posted on: 01 April 2010 at 11:27 hrs

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