QUIC (Quick UDP Internet Connections) is a new generation Internet protocol that speeds online web applications that are susceptible to delay, such as searching, video streaming etc., by reducing the round-trip time (RTT) needed to connect to a server. By replacing TCP with UDP and encrypting most of its payload, QUIC reduces the time it […]
How I Use NMAP in Penetration Testing Engagements
As a network security engineer, among tens of other tasks, I run also security assessment and penetration testing projects. One of the most popular and widely used network scanning tool is NMAP. This is one of the tools that I use at the beginning of a penetration testing engagement and helps tremendously in identifying targets, […]
KRACK WiFi Vulnerability – WPA2 has been breached
On October 16, 2017 a serious security vulnerability has been published by researchers from KU Leuven, a university in Belgium. This has to do with WPA2 protection in WiFi networks, which is the modern security standard considered to be very safe so far. This vulnerability has to do with the WPA2 technology itself and is […]
How to Scan your Network for MS17-010 SMB Eternalblue Vulnerability
Last week the whole world, and especially the information security community, has been buzzing around the massive ransomware attacks that infected thousands of computers in hundreds of countries. But how did all started? Many of you know the story, but let’s summarize it once again: NSA had developed some secret exploits that took advantage of […]
How to configure Cisco Router with IOS Firewall Functionality – CBAC
For a low budget firewall functionality, a Cisco router with the proper IOS version can work as a network firewall providing stateful protocol inspection using the Context-Based Access Control (CBAC) feature. Many people use normal Access Control Lists on Cisco routers for traffic filtering and protection. However, a normal ACL is just a static packet […]
Password Security for Cisco IOS Devices
The use of password protection in any Cisco device is of paramount importance since passwords provide the first level of defence against unauthorised access to our Cisco networks. Especially on terminal lines (either console line or VTY lines), the use of passwords is a fundamental element of security. The following techniques enable you to control […]
Protecting the Telnet VTY Lines of Cisco Devices
There are usually 5 VTY lines on Cisco routers (VTY 0 to 4). An attacker can perform a Denial of Service attack by opening several simultaneous Telnet or SSH connections to the router, thus occupying all available lines and prohibiting the legitimate administrators for managing the device. To protect from this kind of attack, we […]