02 October 2009

Servers

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

02 October 2009

Don't Mix and Match Those Domains

Many organisations like to do land grab with domain names by purchasing the same name with different generic top-level domains (e.g. .com, .net, .info), country code top-level domains (e.g. .uk, .es, .fr), and multiple second-level domains (e.g. .co.uk, .org.uk). Then of course there are mis-spellings, similar sounding words, brand names and trademarks.

Well all that leads to complexity, and it's not uncommon for many domains to be aliased to the same site in a way that any of them can be used to access the complete web site.

But it can get especially messy when SSL is enabled on some or all of the site too. Inevitably there end up being certificate warnings. Some organisations should know better. So when I was searching for providers of online and business privacy "seals",

Partial screen capture showing search engine results including SSL links to pages on the www.truste.org domain including https://www.truste.org/pvr.php?page=complaint

I was very surprised to click on the link to an SSL page which was reported as using an invalid certificate.

Partial screen capture showing the browser's warning message about the page's SSL certificate that says 'www.truste.org uses an invalid security certificate' and 'The certificate is only valid for *.truste.com'

Actually the certificate was fine, it just wasn't valid for the .ORG domain. Perhaps they had hoped the wildcard SSL certificate *.trust.com would somehow cater for *.truste.* - no.

Partial screen capture showing the browser's information about the certificate which says 'You are about to override how Firefox identifies this site - Legitimate banks, stores and other public sites will not ask you to do this' and 'Certificate belongs to a different site, which could indicate an identity theft'

Identity theft? Privacy? But apart from these configuration issues, isn't it just very confusing to have many different domains appearing in search engine results? How does this duplicate content affect their search engine ranking? Does it undermine trust in the brand? Should the SSL part of the site be indexed at all? Perhaps. Who makes these decisions? Is it the developers, the person who configured the site or does the business have a viewpoint?

I overheard a (loud) mobile telephone conversation this week in which a marketing manager* was apologising for a problem but they "did not know any of the technicalities". Mmmm, who is accountable? Make it your business to know.

[* Security and technology managers should also understand their organisation's business objectives.]

Posted on: 02 October 2009 at 07:56 hrs

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29 September 2009

IP Address Restrictions and Exceptions

It's common for access to some web sites to be restricted to users from particular Internet Protocol (IP) addresses. This is usually in addition to some other identification and authentication method. But other IP addresses are often added to this "allow list" and these should not necessarily be trusted in the same way.

Photograph of a sign with an exclamation mark on a yellow triangle that reads 'Caution - Traffic management Trial - DO NOT MOVE' on a construction site boundary's wire barrier

In a typical scenario, a web site hosted on the internet that is used to administer another web application might be restricted to the company's own IP addresses. Then the developers say they need to check something on the live site, or another server needs to index the content, or someone wants to work from home for a while, or the site needs to be demonstrated at a client's location. All these additional IP addresses are added to the "allow list". These restrictions may be being applied at a network firewall, traffic management system, at the web server, in the application itself, in intrusion detection systems or in log analytical software, or in many of these. These are difficult to manage and in time there will be many IP addresses that no-one knows why they are allowed unless they are carefully documented, and subject to a fixed time limit when they are confirmed again by an appropriate person or removed. These extra addresses are quite often hard for someone else to guess.

However, there is another area where IP addresses are added to "allow lists", and this is for remote monitoring and testing services. These might be checking uptime, response times, content changes, HTML validation or security testing. The service providers publish the IP addresses of the source systems so that companies can specifically allow access to their web sites. Since the number of these services is relatively small, it's not too difficult to find which one might give access to areas of a web site or web application that the public (and malicious people) should not be able to get to. The particular danger here is that the IP addresses might be excluded from monitoring and logging, and therefore even a diligent web site manager might not realise for example the uptime monitoring service is making unusual, or excessive, requests.

Although it is not likely a malicious person is using this "trusted" address unless routing has been compromised as well, problems can go undetected, from what might seem to be a legitimate source. The IP address may have been typed incorrectly, or worse, the restrictions/exceptions may not have been implemented correctly allowing more addresses to have the privileged access than intended. Not logging a user's session is privileged access.

Allow traffic through, but be very specific what is allowed and monitor what's going on. Review all the exceptions periodically. Be especially careful about anything that bypasses authentication (such as allowing a search engine to crawl restricted-access content) on an otherwise public site.

Posted on: 29 September 2009 at 10:18 hrs

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04 August 2009

Do You Have SSL Configured Correctly?

Do You Have SSL Configured Correctly? Let me start by saying that "correctly" means "best for you". There isn't a single correct answer, although there are certainly some "don'ts" that apply in every situation.

This information is not about whether to use SSL, and is mainly for your systems folk (or hosting company), but do read on and perhaps gain a better understanding.

Partial screen capture of a report from the SSL Labs Public SSL Server Database showing the host name, IP address, an overall score and part of a bar chart

Ivan Ristić recently announced the SSL Server Rating Guide (draft 10, 21 July 2009) and an associated online assessment tool called the Public SSL Server Database. These had reminded me to post my comments last Tuesday about the slightly related Colour Overload with IE8 Tab Grouping.

The SSL Labs' resources describe, and allow you to check, the SSL configuration of your own, or any other public site that has SSL enabled. The checks span the certificate and three categories of web server configuration settings. Previously, it needed more specialist tools that most people wouldn't have the time or inclination to use.

The rating guide contains much useful information, but will be too detailed for many people. However, do read the "Minimal Configuration Requirements" and pass these on to appropriate person responsible for the configuration and operation of your own web sites. Not every site needs an overall rating of 73 or 85 or whatever. You'll see in Table 6 of the guide, an idea of what might be suitable for a range of web site types.

After all, your competitors, and some customers, have probably already checked your site.

Posted on: 04 August 2009 at 17:56 hrs

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16 June 2009

FTP is not an Option

Many websites are updated using File Transfer Protocol (FTP). Don't do it.

A discussion thread How Do You Store FTP Login Information For Your Clients? highlighted what common practices are, but almost entirely missed the issues of transfer of login credentials over unencrypted channels, privileged access to the whole of the server, account sharing, password and user management.

... [I] also put the info in the client file folders (actual paper client folders) for future reference and sometimes in Outlook business Contact Manager...

It's no surprise that some of the most serious hacks are suspected of being undertaken using compromised FTP accounts.

FTP is not an option. Ask your hosting company or systems staff to disable FTP services and block all traffic to/from your web servers on TCP ports 20 and 21, at your network firewall.

Posted on: 16 June 2009 at 09:28 hrs

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26 May 2009

System Hardening

Hardening the underlying server operating system is an important fundamental task to help protect your web applications.

For example, the Payment Card Industry Data Security Standard (PCIDSS) requirement 2.2 states:

Develop configuration standards for all system components. Assure that these standards address all known security vulnerabilities and are consistent with industry-accepted system hardening standards.

Two United States organisations producing guidance in this field are:

These are detailed documents and all the recommendations may not be appropriate for your own situation.

Posted on: 26 May 2009 at 10:56 hrs

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17 April 2009

Web Application Security in the Cloud - Part 1

There have been some good discussions recently on the security of cloud computing services. Are you using or considering using external cloud computing for data storage or to undertake business functions?

A recent post A follow-up on SaaS & Cloud Risk reminded me to raise the topic here. The posting highlighted comments on The Register regarding Multi-site Bug Exposes Cloud Computing's Dark Lining included one by Raife Edwards:

IF... you own, and run, your own servers, or systems/software... AND, a "common vulnerability" exists, and is exploited... You MAY be vulnerable... you MAY have a security issue... you MAY be targeted... you MAY not have adequately protected your system... you MAY be hit by the problem... you MAY have issues, and losses... possibly.

If, however, you are dependent upon any, EXTERNAL, single point-of-attack/vulnerable-point... then you WILL be hit... you WILL be affected... you WILL have losses... and you WILL be totally-dependent upon EXTERNAL-interests in "fixing", and recovering... based upon THEIR competence, and on THEIR time-table... and, to suit THEIR perception of THEIR interests.

Does this affect you? Not sure? Does your business use any of the following (the categories and terminology overlap)?

  • software as a service (SaaS)
  • platform as a service (PaaS)
  • infrastructure as a service (IaaS)
  • hosted application
  • application service provider (ASP)
  • cloud computing
  • online office application (e.g. Microsoft Business Productivity Online Standard Suite, Google Docs)
  • external web mail (e.g. Hotmail, Gmail, Live Mail)
  • peer-to-peer services (e.g. Skype)
  • online backup and synchronisation (e.g. Iron Mountain, iDisk, Live Mesh)
  • other people's content included directly into your software applications (e.g. news feeds, maps)
  • third party online service (e.g. address lookups, payment gateways).

If so, perhaps answer these three questions. Does it matter...

  • if someone else deletes, or an unauthorised person views, your data?
  • in which geographic location your data are stored?
  • if your data or service are unavailable for more than 10 minutes?

If you answered "yes" to any of the above, take time to consider what the effects would be if any of your data was stolen or the service was unavailable for an hour, a day or a week. The considerations are very similar to any other business decision, but it's easy to forget the trust we are placing in another party.

The key security issues to review are software liability, right to audit, service level agreement (SLA), security testing plans, authentication policies, intellectual property, storage locations, system isolation, data encryption in transit and at rest, backup and recovery, archival, support, complaints procedure, contract jurisdiction and legal compliance. If you have cyber liability insurance, you will also need to check whether these cloud services are covered.

In Part 2 (of 2) on Tuesday, I'll highlight some more recent cloud computing issues and provide links to additional discussions.

Update 27th November 2009: See also Cloud Computing Risks.

Posted on: 17 April 2009 at 11:03 hrs

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13 November 2008

A Cry for Help Which Made Me Want to Cry

E-consultancy.com has many excellent online marketing and e-commerce resources, and I read the blogs and forums regularly. The following posting appeared on the forum a couple of days ago:

Partial screen capture of posting to the e-consultancy.com forums asking 'Can anyone tell me if there is a way of finding out who hosts your website? We  need to find out who is hosting our website any help would be appreciated.'

This cry for help worried me. Although the forum replies were helpful, it did make me wonder how many other web site owners have no idea where their web site is hosted.

If this is really the case here, it probably means the owner doesn't have all the resources to rebuild the site elsewhere and possibly is without back-ups of the data. And what about the intellectual property ownership? It's something which all developers should be discussing with their customers. My first suggestion would have been to contact the development company. A cursory examination of the source code reveals:

Partial screen capture of page source code with a commented out hyperlink to the designers Osmodus

This company even showcases the site:

Partial screen capture showing the Gluttonous Gardener web site featured on the Osmodus portfolio pages

Now, we have no idea of the background and cannot guess if there is anything amiss. But the site is a card payment enabled e-commerce site, and surely the owner has had to comply with the Payment Card Industry (PCI) Security Standards Council's Data Security Standard (DSS)? Knowing where your web site is hosted would be one of the earlier things to discover.

Let's hope it's sorted soon.

Posted on: 13 November 2008 at 14:52 hrs

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24 October 2008

Partition the Web Server

Setting up a web server incorrectly can be difficult to change later. Isolating the operating system from web site files and other data using separate partitions or physical devices needs to be done during server commissioning.

It would be usual to have at least three partitions on a typical web server:

  • The operating system
  • The web site files (scripts and static files such as images and style sheets)
  • Server logs

This allows you to restrict permissions - so that if the web site is compromised, it is harder to access the operating system files, and to ensure that logs don't grow excessively and use up all the available space.

Your own data - the database and perhaps other files - should be stored seperately. If possible this should be on other servers, but if not, on a separate partition.

If you allow any user uploaded content, you should also consider storing this on another separate partition, and in any case, never in sub-directories of the web site root. This is to prevent direct access to possibly malicious file content by directly requesting the address in a browser and to ensure the files are stored in an area with limited permissions.

Posted on: 24 October 2008 at 06:42 hrs

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10 October 2008

Plain FTP and PCIDSS

In my post earlier this week on Server Login Protection, I mentioned how file transfer protocol (FTP) is commonly used, and should not be. A data breach this week hints that FTP was the method of access that lead to the data theft.

The Breach blog reported a breach involving Gloria Jean's Coffees' e-commerce site. Their privacy and security statement aludes to higher standards:

Security
Your purchases at gloriajeans.com are safe. Our site has security measures in place to protect the loss, misuse and alteration of information under our control. We make use of appropriate commercially available software to encrypt order information.

The notification letter to the New Hampshire Department of Justice in the United States (US) says the company:

Locked down File Transfer Protocol (FTP) to specific IP's and implemented SSL encryption to this service for our website

But the strange thing is that it is an e-commerce site and that some of the data stolen was credit card information - card number, name, address and card verification value (CVV), also known as the card security code (CSC) - obtained by modification of the application scripts on the web server. In other words, inbetween the encrypted transfer (using SSL) to the web server and before sending this by an encrypted method to the payment gateway.

Enforcement of the Payment Card Industry (PCI) Data Security Standard (DSS) is much further advanced in the US. So either the site wasn't compliant in which case large fines are winging their way towards Gloria Jean's Coffees Corp, or the auditors may have missed something important here.

See also the related Keeping Up-to-Date with Security Breaches.

Posted on: 10 October 2008 at 07:02 hrs

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07 October 2008

Server Login Protection

The login usernames and passwords for access to the server(s) hosting your web site or application must be protected. If someone has access to your web site's files or the server's operating system, they can potentially alter, delete, copy or add anything they want.

This means every person who requires access having a unique login, and the process of identifying the person and authentication should occur over an encrypted channel (e.g. virtual private network (VPN)). Conventional file transfer protocol (FTP) should never be used, and the service should be disabled or uninstalled in the same way as any other un-necessary service. The FTP log in process is not secure and can lead to the details been stolen and sold to criminals.

Put restrictions on as many of these as possible:

  • Who can log in
  • What they need to know/have/be to log in
  • From where can they log in
  • What they can access once logged in

Passwords should be forced to expire, be complex (e.g. length, mixture of case, alphanumerics) and do not allow password re-use (changing a password back to one used recently). Ensure you:

  • Change all usernames and passwords when your web site goes live
  • Log all failed and successful login attempts
  • Log what is done by users
  • Review the logs frequently
  • Review all user accounts periodically and their permissions
  • Revoke accounts promptly which are no longer needed

Watch out especially for accounts used by external or temporary staff, as these can sometimes be forgotten about. Avoid giving access if you can - upload approved modifications yourself for example - at least you will have a record of what has been altered.

I'll include one of my favourite illustrations: the ICRA (formerly the Internet Content Rating Association) web content label generator tool, allows you (or your developers, designers, etc) to give ICRA your own FTP details:

Partial screen capture of the form on the ICRA web site asking for the FTP address, username and password

"What happens next?" indeed.

Posted on: 07 October 2008 at 18:41 hrs

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