CVE-2025-4366 in pingora
Summary
by MITRE • 05/22/2025
A request smuggling vulnerability identified within Pingora’s proxying framework, pingora-proxy, allows malicious HTTP requests to be injected via manipulated request bodies on cache HITs, leading to unauthorized request execution and potential cache poisoning.
Fixed in: https://github.com/cloudflare/pingora/commit/fda3317ec822678564d641e7cf1c9b77ee3759ff https://github.com/cloudflare/pingora/commit/fda3317ec822678564d641e7cf1c9b77ee3759ff
Impact: The issue could lead to request smuggling in cases where Pingora’s proxying framework, pingora-proxy, is used for caching allowing an attacker to manipulate headers and URLs in subsequent requests made on the same HTTP/1.1 connection.
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Analysis
by VulDB Data Team • 08/07/2025
The vulnerability described in CVE-2025-4366 represents a critical request smuggling flaw within Pingora's proxying framework, specifically affecting the pingora-proxy component. This issue emerges from the improper handling of HTTP request bodies during cache HIT scenarios, creating a pathway for malicious actors to inject unauthorized requests into the system's processing pipeline. The vulnerability exploits the fundamental mechanics of HTTP/1.1 connections and caching mechanisms, where the proxy framework fails to properly sanitize or validate request bodies that are subsequently processed during cache hit operations.
The technical implementation of this flaw involves the manipulation of HTTP request bodies to inject additional requests or modify existing request parameters during cache HITs. When a cached response is served, the proxy framework processes the request body in a manner that allows attackers to smuggle subsequent requests through the same HTTP/1.1 connection. This occurs because the framework does not adequately separate or validate the boundaries between different request components during the caching process. The vulnerability specifically targets the interaction between the HTTP request parsing logic and the caching layer, creating an environment where malicious input can be executed as part of legitimate processing flows.
From an operational impact perspective, this vulnerability creates significant security risks for systems relying on Pingora's proxying framework for caching operations. Attackers can leverage this flaw to manipulate headers and URLs in subsequent requests, potentially gaining unauthorized access to resources or bypassing security controls. The attack vector becomes particularly dangerous when multiple requests are processed over the same connection, as the injected requests can be executed in the context of the original connection's security boundaries. This capability directly violates the principle of request isolation and can lead to unauthorized data access, service disruption, or even complete system compromise depending on the target applications.
The mitigation strategy for CVE-2025-4366 requires immediate deployment of the fixes referenced in the commit hashes provided, which address the core parsing and validation logic within the pingora-proxy framework. Organizations should implement comprehensive monitoring for anomalous request patterns and cache behavior that might indicate exploitation attempts. The fix likely involves enhanced input validation, proper request body isolation during cache operations, and improved handling of HTTP/1.1 connection state transitions. From a security control standpoint, this vulnerability aligns with CWE-444, which addresses HTTP request smuggling, and maps to ATT&CK technique T1190, representing exploitation of remote services through HTTP smuggling. Organizations should also consider implementing additional layers of protection including web application firewalls, connection monitoring, and regular security assessments of their proxy configurations to prevent similar vulnerabilities from emerging in other components of their infrastructure.