This tweet mentions a bypass technique for an ingress Web Application Firewall (WAF) using a Layer 7 polyglot payload to trigger an Out-Of-Band (OOB) DNS callback. The bypass targets Layer 7, which is the application layer in the OSI model, indicating that the attack is designed to evade detection by manipulating the HTTP/HTTPS traffic in a way that the WAF cannot properly filter or inspect. The mention of a DNS callback suggests that the payload sends data or triggers requests that cause DNS queries to an attacker-controlled server, which can indicate successful exploitation or data exfiltration. Polyglot payloads are specially crafted inputs that can be interpreted in multiple ways depending on the context, making them effective in bypassing security filters that look for specific attack signatures. Ingress WAF suggests the WAF deployed at the entry point of the application or network, often used in cloud-native environments or Kubernetes clusters to filter incoming traffic. This type of bypass shows the complexity and evolving nature of web security threats where attackers creatively exploit application-layer protocols to evade protective systems like WAFs.
Original tweet: https://twitter.com/e_Liam_/status/2029673365284192263