CRLF-Powered Desync Attacks: Beheading HTTP Streams
Summary
This research paper argues that HTTP Header Injection, specifically leveraging CRLF (Carriage Return Line Feed) characters, is a severely underestimated attack vector. The authors demonstrate how these injections can lead to "beheading" HTTP streams, enabling catastrophic consequences beyond typical Cross-Site Scripting or open redirect vulnerabilities.
IFF Assessment
This article details a powerful new attack technique that exploits fundamental HTTP communication, posing a significant threat to web application security.
Severity
CRLF injection can lead to a complete de-synchronization of HTTP streams, allowing attackers to inject malicious responses or commands. This has a high potential for impact on confidentiality, integrity, and availability.
Defender Context
Defenders need to be aware of CRLF injection vulnerabilities, as they can be more impactful than commonly recognized web attack types. Robust input validation and sanitization are crucial to prevent the manipulation of HTTP headers and the subsequent de-synchronization of communication streams.