Elusive Thoughts

 Introduction  As Crypto currency technologies are becoming more and more prevalent, as the time is passing by, and banks will soon start adopting them. Ethereum blockchain and other complex blockchain programs are relatively new and highly experimental. Therefore, we should expect constant changes in the security landscape, as new bugs and security risks are discovered, and new best practices are developed [1].This article is going to discuss how to perform a source code review in Ethereum Smart Contracts (SCs) and what to look for. More specifically we are going to focus in specific keywords and how to analyse them.  The points analysed are going to be: User supplied input filtering, when interacting directly with SC Interfacing with external SCs Interfacing with DApp applications SC formal verification Wallet authentication in DApp SC Programming Mindset When designing an SC ecosystem (a group of SCs, constitutes an ecosystem) is it wise to have some specific concepts ...

External Service Interaction & Out-of-Band Resource Loads — Updated 2026 External Service Interaction & Out-of-Band Resource Loads Host Header Exploitation // SSRF Primitives // Infrastructure Pivoting SSRF Host Header Injection CWE-918 OWASP A10:2021 Cache Poisoning Updated 2026 In the recent past we encountered two relatively new types of attacks: External Service Interaction (ESI) and Out-of-Band Resource Loads (OfBRL). An ESI [1] occurs only when a web application allows interaction with an arbitrary external service. OfBRL [6] arises when it is possible to induce an application to fetch content from an arbitrary external location, and incorporate that content into the application's own response(s). Taxonomy Note (2026): Both ESI and OfBRL are now classified under OWASP A10:2021 — SSRF and map to CWE-918 (Server-Side Request Forgery). ESI also maps to CWE-441 (Unintentional Pro...

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...

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...