CVE-2022-36760 in Communications Unified Assurance
Summary
by MITRE • 01/17/2023
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in mod_proxy_ajp of Apache HTTP Server allows an attacker to smuggle requests to the AJP server it forwards requests to. This issue affects Apache HTTP Server Apache HTTP Server 2.4 version 2.4.54 and prior versions.
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Analysis
by VulDB Data Team • 04/05/2025
The CVE-2022-36760 vulnerability represents a critical HTTP Request Smuggling flaw within the mod_proxy_ajp module of Apache HTTP Server, a widely deployed web server solution that serves as a crucial component in many enterprise environments. This vulnerability stems from inconsistent interpretation of HTTP requests, specifically when the server processes requests that are forwarded through the AJP (Apache JServ Protocol) connector to backend application servers. The flaw occurs when the Apache server receives HTTP requests that contain multiple Content-Length headers or when there are inconsistencies between the Transfer-Encoding and Content-Length headers, creating ambiguous parsing conditions that attackers can exploit to manipulate request boundaries.
The technical implementation of this vulnerability leverages the inherent differences in how Apache HTTP Server and backend AJP servers interpret HTTP request boundaries and header values. When mod_proxy_ajp processes requests, it may interpret the same HTTP request differently depending on the order of headers, presence of duplicate headers, or variations in header formatting. This inconsistency allows an attacker to craft malicious requests that appear as single requests to the Apache server but are interpreted as multiple requests by the backend AJP server. The vulnerability specifically affects Apache HTTP Server version 2.4.54 and earlier, making it particularly concerning given the widespread deployment of these server versions across enterprise and cloud environments.
The operational impact of CVE-2022-36760 extends beyond simple request manipulation and can enable attackers to perform various malicious activities including bypassing access controls, accessing restricted resources, performing unauthorized operations against backend applications, and potentially executing arbitrary code. Attackers can exploit this vulnerability to inject requests that are processed by the backend application server while appearing to be legitimate requests to the Apache server, creating a scenario where the backend server processes requests that should not be accessible to the attacker. This issue falls under CWE-444, which specifically addresses HTTP Request Smuggling vulnerabilities, and aligns with ATT&CK technique T1190, which covers the exploitation of vulnerabilities in web applications through HTTP request manipulation.
Mitigation strategies for CVE-2022-36760 require immediate attention from system administrators and security teams, with the most effective approach being the upgrade to Apache HTTP Server version 2.4.55 or later, which includes fixes specifically addressing the inconsistent HTTP request interpretation. Organizations should also implement strict header validation mechanisms, disable the mod_proxy_ajp module if it is not essential for operations, and deploy web application firewalls that can detect and block suspicious request patterns. Additionally, network segmentation and monitoring solutions should be enhanced to detect anomalous request behaviors that might indicate exploitation attempts, as the vulnerability can be particularly subtle and difficult to detect through conventional security scanning methods.