CVE-2024-33452
Description
A flaw was found in the OpenResty lua-nginx-module. Affected versions of this component allow a remote attacker to conduct HTTP request smuggling via a crafted HEAD request. The attacker can use this attack to bypass any frontend proxy protection, serve malicious responses to all the users in the same connection pool, and capture the responses of other users.
Statement
This vulnerability marked as Important not just a Moderate flaw, because it enables a class of HTTP Request Smuggling attacks that bypass normal security boundaries between front-end and back-end components. While typical HEAD requests should discard the body and ensure no desynchronization occurs, the lua-nginx-module flaw causes the request body to be treated as a new, legitimate HTTP request. This breaks the request-response mapping (queueing) in HTTP/1.1 persistent connections. In modern architectures where API gateways (like Kong) sit behind a front-end CDN or reverse proxy (such as Nginx, Cloudflare), this leads to severe security consequences—including response queue desynchronization, serving malicious or sensitive responses to other users, bypassing authentication/authorization rules, and ultimately allowing an attacker to hijack cross-user sessions and sensitive data.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.7 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | Low | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
Understanding the Weakness (CWE)
Integrity,Non-Repudiation,Access Control
Technical Impact: Unexpected State; Hide Activities; Bypass Protection Mechanism
An attacker could create HTTP messages to exploit a number of weaknesses including 1) the message can trick the web server to associate a URL with another URL's webpage and caching the contents of the webpage (web cache poisoning attack), 2) the message can be structured to bypass the firewall protection mechanisms and gain unauthorized access to a web application, and 3) the message can invoke a script or a page that returns client credentials (similar to a Cross Site Scripting attack).
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