ALBeast: a simple misconfiguration to a complete authentication bypass
The ALBeast vulnerability represents a critical security flaw in AWS Application Load Balancer (ALB) authentication implementation that could lead to complete authentication bypass. This vulnerability, affecting over 15,000 applications, stems from improper validation of AWS-specific header claims and misconfigured security groups, allowing attackers to forge authentication tokens and impersonate legitimate users. The issue highlights the importance of proper JWT validation and security group configuration in AWS ALB implementations.