This document provides instructions for solving a DEFCON 2019 Web quals challenge involving accessing an internal server through various techniques. It outlines 3 steps: 1) Analyzing the proxy settings to access the internal server, 2) Gaining internal access through cross-site scripting (XSS) or DNS rebinding, and 3) Using SQL injection to retrieve the flag by exploring the database schema. The challenge involves analyzing the proxy configuration, exploiting XSS or DNS rebinding vulnerabilities to bypass access restrictions, and using SQL injection to find the flag stored in the database.
- The document discusses breaking an RSA encryption challenge by exploiting weaknesses in the key generation algorithm. Specifically, it generates private exponents d within a small bounded range, and uses a small prime ppp, making it possible to brute force.
- It explains using the Howgrave-Graham lemma and lattice-based techniques like LLL reduction to construct polynomials with the same root to recover the private exponent and break the encryption. While this worked, it took too long to solve all challenges within the time limit.
- The solution found was OOO{Br3akingL!mits?}, indicating the challenge was broken by exploiting limitations in the key generation process.
This document provides instructions for solving a DEFCON 2019 Web quals challenge involving accessing an internal server through various techniques. It outlines 3 steps: 1) Analyzing the proxy settings to access the internal server, 2) Gaining internal access through cross-site scripting (XSS) or DNS rebinding, and 3) Using SQL injection to retrieve the flag by exploring the database schema. The challenge involves analyzing the proxy configuration, exploiting XSS or DNS rebinding vulnerabilities to bypass access restrictions, and using SQL injection to find the flag stored in the database.
- The document discusses breaking an RSA encryption challenge by exploiting weaknesses in the key generation algorithm. Specifically, it generates private exponents d within a small bounded range, and uses a small prime ppp, making it possible to brute force.
- It explains using the Howgrave-Graham lemma and lattice-based techniques like LLL reduction to construct polynomials with the same root to recover the private exponent and break the encryption. While this worked, it took too long to solve all challenges within the time limit.
- The solution found was OOO{Br3akingL!mits?}, indicating the challenge was broken by exploiting limitations in the key generation process.