CyberRota Analysis
AI-GeneratedThe blaze library, specifically versions prior to 0.23.18 and 1.0.0-M42, is vulnerable due to the ability of unauthenticated remote clients to inject arbitrary HTTP header names and values through chunked-body trailer fields. This can lead to significant security risks, including spoofing client IP addresses, bypassing trust decisions based on proxy-set headers, and potentially compromising internal authorization mechanisms. Organizations utilizing http4s applications with BlazeServerBuilder over HTTP/1.1 should prioritize upgrading to the patched versions to mitigate these risks.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD Description
blaze is a Scala library for building asynchronous pipelines, with a focus on network IO. Prior to 0.23.18 and 1.0.0-M42, blaze-server can merge HTTP/1.1 chunked-body trailer fields into Request.headers. Because trailer fields are attacker-controlled, an unauthenticated remote client can inject arbitrary header names and values, including X-Forwarded-For and internal authorization headers, that a fronting proxy sanitized from the request-header section, bypassing header-based trust decisions in the application. Any http4s application using BlazeServerBuilder over HTTP/1.1 whose routes or middleware trust proxy-set headers, including X-Forwarded-For, X-Real-IP, and X-Forwarded-Host, is affected. If a fronting proxy strips or normalizes those headers but forwards chunked bodies with trailers intact, an attacker can spoof client IP for allow-lists, rate limits, or auditing, forge the https scheme, or inject internal authorization headers. A promoted Connection: close trailer is also honored, allowing attacker-controlled termination of pooled backend connections. This issue is fixed in versions 0.23.18 and 1.0.0-M42.