CVE-2020-7658 in meinheld
Summary
by MITRE
meinheld prior to 1.0.2 is vulnerable to HTTP Request Smuggling. HTTP pipelining issues and request smuggling attacks might be possible due to incorrect Content-Length and Transfer encoding header parsing.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 05/23/2020
The vulnerability identified as CVE-2020-7658 affects meinheld versions prior to 10.2, exposing systems to HTTP request smuggling attacks through improper handling of HTTP headers. This flaw stems from inadequate parsing of Content-Length and Transfer-Encoding headers during HTTP request processing, creating opportunities for attackers to manipulate request boundaries and potentially bypass security controls. The vulnerability represents a critical weakness in HTTP protocol implementation that can compromise the integrity of web applications relying on meinheld as their application server.
The technical flaw manifests in meinheld's failure to properly validate and process HTTP headers during request parsing, specifically when multiple Content-Length headers are present or when Transfer-Encoding and Content-Length headers conflict with each other. This misconfiguration allows attackers to craft malicious requests that exploit HTTP pipelining mechanisms, enabling them to inject or manipulate subsequent requests within the same connection. The vulnerability is particularly dangerous because it operates at the HTTP protocol level, affecting the fundamental communication between clients and servers without requiring authentication or specialized privileges.
The operational impact of this vulnerability extends beyond simple data corruption or information disclosure. Attackers can leverage HTTP request smuggling to perform session hijacking, cache poisoning, and cross-site scripting attacks by manipulating how subsequent requests are interpreted by the server. The vulnerability can be exploited to bypass security controls such as web application firewalls, authentication mechanisms, and access control policies. Additionally, the attack surface is broad as any application using meinheld as its underlying HTTP server becomes potentially vulnerable, affecting web applications that rely on proper HTTP header handling for security.
Mitigation strategies for CVE-2020-7658 require immediate patching of meinheld to version 1.0.2 or later, which includes corrected header parsing logic and improved validation of Content-Length and Transfer-Encoding values. Organizations should also implement network-level protections such as proxy servers that normalize HTTP headers before they reach the vulnerable application server. The vulnerability aligns with CWE-444, which describes improper handling of HTTP requests, and maps to ATT&CK technique T1071.004 for application layer protocol manipulation. Security teams should conduct comprehensive testing to ensure that patched environments properly handle edge cases in HTTP header processing and monitor for potential exploitation attempts through network traffic analysis and intrusion detection systems.