Availability
Availability Availability of a site shows if a site is accessible from the Internet.

Availability of a site shows if a site is accessible from the Internet. This term is also about access to a server, database or another entity. As all objects in the Internet are based on comlicated infrastructure, nothing can be available always. The question is how to measure it, what is normal and if we may affect it anyway. The measurement of availability is connected to terms Uptime and Downtime, which show for how long a site is unavailable. However, these values can not create the full view of the situation. There could be many reasons of unavailability - server or connection problems, application error, overload of the site and so on. To avoid or shorter the failures, it is needed to supervise the site and analyze the errors, if they happen. For these purposes there are special monitoring tools, which help to increase to availability of the site, collect statistics and provide necessary information about the errors for fast repair. These tools are called Website Monitoring services.

  • CM.Glossary.WebsiteMonitoring
  • CM.Glossary.Downtime
  • CM.Glossary.Uptime
more glossary
"

The global monitoring system is quite useful -
as most of my outages are really regional outages out of my control. It helps to know this.

"
- Rick
Shellshock vulnerability online check

Considering the recently discovered Shellshock vulnerability, HostTracker has created a tool for testing it.

Check your server for vulnerability

How does it work?

It is developed for a Linux server with a web server installed on it. The algorithm is very simple. We consequently generate 4 http requests:

  • 1. Ordinary request
  • 2. The request tries, using vulneratility, post a "harmful" cookie which causes 2-seconds delay in respond to our special http request.
  • 3. The request tries, using vulneratility, post a "harmful" cookie which causes 4-seconds delay in respond to our special http request.
  • 4. Same as #3

How to understand the result?

We compare response time for all 4 requests. Three situation are possible:

  • 1. Vulnerability found. We may affirm that if the difference in responses is about 2 seconds for requests without cookie and with 2-second-delay cookie, as well as for requests with 2 and 4-second delay cookie. It means that our request was able to use the vulnerability and set these cookies.
  • 2. Vulnerability not found. All the requests have about the same response time. The cookies, likely, were not installed because there is no vulnerability.
  • 3. Uncertain situation. If the response time differs widely, without coincidence with preset by cookies delay, we can not say for sure. It could be if the server is under high load. To check this, we use two requests with same cookies (#3 and #4). If the response time for two same checks varies, we make a conclusion that the response time is not affected by cookies. At least, not only by them. So in this case our method can not detect vulnerability

Safety of checks

Our test can not damage your server. The risk consists of appearance of one extra-cookie, which is used only for our requests and can not affect normal work-flow of your site.

more blog
Thank you for feedback!
 
Reset password
Sign In
Sign Up
Prices & packages
Our monitoring network
Home > Reset password
 
Share:
Send to Twitter Send to Facebook Send to LinkedIn Share on Google+
Blogs:
HostTracker blog HostTracker page on Facebook