Tag Archives: Firefox

Making Vulnerable Web-Applications: XXS, RCE, SQL Injection and Stored XSS ( + Buffer Overflow)

In this post I will write some simple vulnerable web applications in python3 and will show how to attack them. This is all for educational purposes and for complete beginners. So please don’t be too hard on me. 😉

Vulnerability Examples

As a first step I will create a basic web-application using twisted python web server (you can learn more about it in “Making simple Nmap SPA web GUI with Apache, AngularJS and Python Twisted“).

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Potential RCE in Nessus 7 and attacks on Vulnerability Scanners

A few days ago I saw an interesting youtube video (UPD. 14.05.18 Not available anymore) in my Facebook feed. It is demonstrating the exploitation of the RCE vulnerability in Tenable Nessus Professional 7.0.3. Currently we have very few information about this vulnerability: only youtube video, which is mentioned only on ExploitWareLabs facebook page.

Nessus 7.0.3 RCE

While there is no exploit in public access, it’s hard to say how it actually works. It’s also not clear what versions of Nessus are affected. 7.0.3 is the latest version currently. Because of API disabling in Nessus 7 many users are still on 6.11.3. It is not clear whether they are affected or not.

This even can be a fake video. Therefore, I specifically write “potential RCE”. I will update this post when more data is available.

UPD. 14.05.18 In the comments to my Facebook post anonymous account Destring Portal posted a comment with the second video of Nessus RCE exploitation and it seems, that it was made by the same author. In this video, the author runs a remote shell on the Nessus host and executes various commands. I will add review of this second video bellow.

Nessus RCE second video

UPD. 10.05.18 Renaud Deraison, Co-Founder and CTO of Tenable, commented on my post at Linkedin:

Our research team studied the video and we have several reasons to doubt its authenticity. We’ve conducted a thorough audit over the last 48 hours based the few details that are in the video and didn’t find anything. We reached out the researcher and instead of replying he removed the video*. We’ll communicate if indeed there is a risk.

In general, you are right though – the security of scanners is of paramount importance. This actually is a topic I’ve been extremely worried about ever since the early days of Nessus. We have a number of security mechanisms in place (interpreted language for the detection scripts, ciphered temporary files, very limited runtime environment) which really aim to limit the risk of being exploited but also to mitigate the risk should the scanner be compromised. I actually did a few talks in the past about scanning “rogue hosts” and we continue to treat all input as hostile.

Again, we’re continuing to investigate the matter and will let you know if we find anything.

* currently video is still available on the same address; it could be probably blocked for some time. (UPD. 14.05.18 Not available anymore)

In any case, it’s a good reason to talk about vulnerabilities of such kind, how they appear and how to protect Vulnerability Scanners from attackers.

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Making simple Nmap SPA web GUI with Apache, AngularJS and Python Twisted

The last time I was developing dynamic web applications years ago. I used CGI and PHP back then. 🙂 Now I am really interested in a modern approach, when you have a Single Page Web Application (SPA) written in HTML and JavaScript, that makes http requests to some external API.

It’s pretty cool, because your application becomes API-centric naturally. You work on human interface and improve integration capabilities at the same time. And the task of securing your web app mostly reduces to securing your formalized API.

nmap SPA GUI

The very best way to learn something new is to write a post about this stuff. 😉 Here I will reproduce my own steps of making a very basic web app:

  1. Launch Apache web-server with http/https.
  2. Make a simple API service: Nmap wrapper.
  3. Make a web-application with “multipage” experience. There should be at least two pages: Scan and About.
  4. On Scan page it will be possible to input a target (hostname or IP), scan arguments and  launch scan by clicking on the button. The same behavior will be if the target will be passed as a parameter in address bar.
  5. On other pages should be some static text.

As you can see, it is a very limited task, but it should clear up the most confusing parts of the process.

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Burp Suite Free Edition and NTLM authentication in ASP.net applications

As you know, Burp Suit is a scanner for advanced Web Application Security researchers. However, the free version of Burp is more like Firebug analogue, but much more functional.

Let’s see how to install it and use for website analysis. This analysis may be necessary to find vulnerabilities or somehow automate the work with the site. Let’s take, for example, ASP.net applications with NTLM-authorization, which is rather unpleasant to analyze.

Go to the site https://portswigger.net/burp/freedownload and download burp installer as a bash script:

Burp Suite Free Edition

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PHDays VII: To Vulnerability Database and beyond

Last Tuesday and Wednesday, May 23-24, I attended PHDays VII conference in Moscow. I was talking there about vulnerability databases and the evolution process of vulnerability assessment tools, as far as I understand it.

To Vulnerability Database and beyond

But first of all, a few words about the conference itself. I can tell that since the last year the event got even better. I’ve seen lot of new faces. Some people I didn’t know, but they knew me by my blog and accounts in social networks. What a strange, strange time we live in! I was very pleased to see and to talk with you all, guys! 🙂

PHDays is one of the few events that truly brings all Russian community of security professionals together. I’ve seen people I have studied with in university, colleagues from the all places where I have been worked, and nearly all researchers and security practitioners that I follow. Big thanks for the organizers, Positive Technologies, for such an amazing opportunity!

It is also a truly international event. You can see speakers from all over the world. And all information is available both in Russian and English. Almost all slides are in English. Three parallel streams of reports, workshops and panel discussions were dubbed by professional simultaneous interpreters, like it is a United Nations sessions or something, recorded and broadcast live by the team of operators and directors. Final result looks really great.

Video of my presentation:

I was talking too fast and used some expressions that was hard to translate. The translator, however, did an awesome job. He is my hero! 🙂 If you didn’t understand something on video, I made a transcript bellow.

A version without translation for Russian-speakers is here.

Slides:

Unfortunately gif animation is not working in the Slideshare viewer.

Today I would like to discuss vulnerability databases and how vulnerability assessment systems has been evolving. Prior to discussing vulnerability databases I need to say that any vulnerability is just a software error, a bug, that allowing hacker to do some cool things. Software developers and vendors post information about such vulnerabilities on their websites. And there are tons and tones of vendors, and websites, and software products, and vulnerabilities.

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