What is DoS

A Denial of Service (DoS) attack is a method used to disrupt the normal functioning of a server, application, or network by overwhelming it with requests or exploiting its vulnerabilities. Here's how some of the provided concepts relate to DoS:

Exploitation

• Bad Parser Exploitation: Maliciously crafted input (e.g., "><a>) can confuse the parser, leading to crashes or degraded performance.

• N+1 Problem: A single query triggering multiple subsequent queries can amplify the load on a server. For instance:

  • If querying a page with large datasets leads to exponential query execution (N+1 queries), adding more pages can drastically increase server load.
  • Exploiting this issue can multiply the DoS effect.

• Blind SSRF and Slowloris Attack:

  • Blind SSRF (Server-Side Request Forgery): An attacker manipulates a server to make unintended requests, potentially entering infinite redirection loops (e.g., app redirects to attacker app, attacker app redirects back to app, ...), tying up server resources.
  • Slowloris: By keeping server sockets open for extended periods (e.g., hanging for 10 seconds), it can exhaust available connections, causing the server to become unresponsive.

• HTTP Pipelining Abuse: Sending multiple requests in a single connection can flood a server, especially if the server mishandles pipelined requests or processes them inefficiently.

• Cache Poisoning: Manipulating cache keys to store incorrect or malicious data can degrade server performance or cause incorrect responses, potentially disrupting services for users.

• Signing DoS: Exploiting authentication mechanisms or cryptographic signing to force heavy processing can lock out legitimate users.