Privilege Escalation Techniques

Posted on Mi 10 August 2016 in Security • Tagged with Linux, Privilege Escalation, rootLeave a comment

This blog post will serve as a cheatsheet to help in my future pentesting experiments and wargames when I am stuck and don't know how to proceed. I hope it will be of use for some people out there. This document will likely change and evolve in future revisions.

In this blog post I will discuss common privilege escalation techniques. I assume that an attack got a foothold into the server by spawning a webshell over SQL-Injections or similar web exploitation vectors.

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Probabilistic data structures to estimate cardinalities and frequencies of massive streams

Posted on Mi 20 Juli 2016 in BigData • Tagged with LogLog-Count, Count-Min-Sketch, Linear Count, Big Data, Stream ProcessingLeave a comment

In the following blog post we will introduce three different Big Data algorithms. More specifically, we will learn about probabilistic data structures that allow us to estimate cardinalities and frequencies of elements that originate from a massive stream of data. This blog post is heavily inspired by a the well written article on probabilistic data structures for web analytics and data mining. I will not cover the mathematics behind those data structures, the beforementioned blog post does that much better. And if not, then you should probably consult the original ...

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What other package managers are vulnerable to typo squatting attacks?

Posted on Do 30 Juni 2016 in Security • Tagged with security, Typosquatting, nuget, cargoLeave a comment

In my last blog post about typosquatting package managers I discussed my findings about attacking the programming language package managers from, PyPi and

This blog contribution generated quite some interest and people subsequently asked themselves whether other package managers might also be vulnerable to this hybrid attack (typosquatting involves a technical and psychological attack vector). During the time I wrote my thesis, I encountered some other package managers. A very good overview of some of the most recent package managers gives the github showcase page about ...

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Typosquatting programming language package managers

Posted on Mi 08 Juni 2016 in Security • Tagged with PyPi,,, security, TyposquattingLeave a comment

Edit: It seems that the blog post and the thesis caused quite some interest. Please contact me under the following mail address, since my mail server on this VPS is constantly down :/ tschachn [|[at]|] hu-berlin [[|dot|]] de

In this blog post I will show how to use the neat JavaScript library chart.js with the well-known Python web-framework Django. As a sample data set I will make use of my workout progress data between May 2016 and August 2016.

  • 17000 computers were forced to execute arbitrary code by typosquatting programming ...
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Nebula Wargame walkthrough Level 10-19

Posted on Di 29 September 2015 in Wargames • Tagged with Linux, Programming, Security, Problem SolvingLeave a comment

Walkthrough of nebula wargame from level 10 to level 19

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Nebula Wargame walkthrough Level 0-9

Posted on Mo 28 September 2015 in Wargames • Tagged with Linux, Programming, Security, Problem SolvingLeave a comment

In this blog post we will walk through the solutions of the levels 0 to 9 of the Nebula wargame, which is hosted on This writeup will force me to memorize commands better and exercise a bit. I fear that this writeup is of no use for other people, since you hopefully want to solve those exercises on your own :)

Level 0 - Finding setuid programs in the filesystem

As the descriptions states you need to find a setuid binary that gets a shell for the flag00 user ...

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