Elusive Thoughts

Web Application Denial of Service Next Level In this tutorial we are going to talk on how to cause maximum down time (including operational recovery processes ) in anything that uses the word Web, this is also known as a Denial o Service Attack. Using this knowledge for malicious purposes is not something I am recommending or approve and I have zero accountability on how you use this knowledge. This is the reason I am providing also with countermeasures on the end of the post.       What Is The Landscape In the past we have seen many Denial of Service attacks, but most of them were not very sophisticated. A very good example would be the Low Orbit Ion Cannon (LOIC). LOIC performs a DoS attack (or when used by multiple individuals, a DDoS attack) on a target site by flooding the server with TCP or UDP packets with the intention of disrupting the service of a particular host. People have used LOIC to join voluntary botnets.[2] All these att...

Introduction The reason for this blog post is to analyse certain types of attacks that relate to cache manipulation and recently resurfaced by various BlackHat and Defcon presentation. More specifically we are interested in the following type of attacks: Web Cache Poisoning Attacks  Web Cache Deception Attacks About the cache Many people fail to understand what exactly what is a Web cache , and therefore, I am going to invest a lot of time to analyse and explain what is a cache from Hacker/Security Professional perspective, when conducting a pentest or simple hacking a site. The cache In computing, a cache is a hardware or software component that stores data so that future requests for that data can be served faster [1]. Hmm interesting, very interesting, also the data stored in a cache might be the result of an earlier computation or a copy of data stored elsewhere [1]. So data might be replicated to other locations within the system that serves the conte...

Introduction The reason for this blog post is to advertise my book. First of all I would like to thank all the readers of my blog for the support and feedback on making my articles better. After 12+ years in the penetration testing industry, the time has come for me to publish my book and tranfer my knowledge to all the intersted people that like hacking and want to learn as much as possible. Also at the end of the blog you will find a sample chapter. About The Author Gerasimos is a security consultant holding a MSc in Information Security, a CREST (CRT), a CISSP, an ITILv3, a GIAC GPEN and a GIAC GAWPT accreditation. Working alongside diverse and highly skilled teams Gerasi- mos has been involved in countless comprehensive security tests and web application secure development engagements for global web applications and network platforms, counting more than 14 years in the web application and application security architecture. Gerasimos further progressing in h...

Intro This post is going to explain how to test a Denial of Service Vulnerability without crashing the actual service. More specifically we will focus on two vulnerabilities a) the slowris vulnerability (also known as Apache Partial HTTP Request Denial of Service Vulnerability) and b) the TLS Renegotiation and Denial of Service Attacks. Apache Partial HTTP Request Denial of Service Vulnerability The target application Apache Server is vulnerable to a denial of service named Slow-DoS attack, due to holding a connection open for partial HTTP requests. Both Apache Versions 1.x and 2.x are vulnerable. Slow HTTP attacks are denial-of-service (DoS) attacks in which the attacker sends HTTP requests in pieces slowly, one at a time to a Web server. If an HTTP request is not complete, or if the transfer rate is very low, the server keeps its resources busy waiting for the rest of the data. When the server’s concurrent connection pool reaches its maximum, this creates a DoS. Slow HTTP attac...