CVE-2020-7611 in http-client
Summary
by MITRE
All versions of io.micronaut:micronaut-http-client before 1.2.11 and all versions from 1.3.0 before 1.3.2 are vulnerable to HTTP Request Header Injection due to not validating request headers passed to the client.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 05/12/2024
The vulnerability identified as CVE-2020-7611 affects the micronaut-http-client library version 1.2.10 and earlier, as well as versions 1.3.0 through 1.3.1 of the Micronaut framework. This security flaw resides in the HTTP client implementation and represents a critical weakness in header validation mechanisms. The vulnerability allows malicious actors to inject arbitrary HTTP headers into requests, potentially enabling various attack vectors including cache poisoning, authentication bypass, and data exfiltration. The issue stems from insufficient input validation within the client's header processing logic, which fails to properly sanitize or validate header values before transmission. This weakness directly maps to CWE-113, which describes improper neutralization of CRLF characters in HTTP headers, a well-documented vulnerability pattern in web applications. The attack surface is particularly concerning for applications that rely on the micronaut framework for HTTP communications, as the vulnerability can be exploited through various means including user-controlled input that flows into HTTP client requests.
The technical exploitation of this vulnerability occurs when applications using the affected micronaut-http-client library pass untrusted input directly into HTTP header values without proper sanitization. Attackers can craft malicious header values containing carriage return and line feed characters that, when processed by the vulnerable client, result in injection of additional headers into the HTTP request. This behavior enables sophisticated attacks such as HTTP response splitting, where an attacker can inject multiple headers that modify the request processing behavior. The vulnerability is particularly dangerous in environments where the HTTP client is used to make requests to external services, as it can be leveraged to manipulate the request flow and potentially gain unauthorized access to backend systems. The flaw operates at the application layer of the OSI model, specifically within the HTTP protocol handling components of the framework, making it accessible to attackers who can influence the header values passed to the client.
The operational impact of CVE-2020-7611 extends beyond simple header injection, as it can enable more sophisticated attacks depending on the application's architecture and the target systems. Applications using the vulnerable library may be susceptible to cache poisoning attacks where malicious headers can manipulate how HTTP responses are cached by intermediate proxies or CDN services. The vulnerability also poses risks for authentication bypass scenarios where attackers can inject headers that modify authentication mechanisms, potentially allowing unauthorized access to protected resources. Additionally, the weakness can facilitate data exfiltration attacks by enabling the injection of headers that redirect request flows or modify response handling. Organizations running applications with vulnerable micronaut-http-client versions face significant risk of compromise, particularly in environments where the framework is used for external communications or where applications process untrusted input that eventually becomes part of HTTP headers.
Mitigation strategies for CVE-2020-7611 focus primarily on upgrading to patched versions of the micronaut-http-client library, specifically versions 1.2.11 and 1.3.2 or later. Organizations should conduct immediate inventory assessments to identify all applications using vulnerable versions and prioritize remediation efforts accordingly. The patch implementation addresses the core validation issue by introducing proper header sanitization mechanisms that prevent CRLF character injection. Security teams should also implement additional defensive measures such as network monitoring to detect unusual header patterns that might indicate exploitation attempts. Application developers should review their code to ensure that no user-controlled input is directly passed to HTTP client header parameters without proper validation and sanitization. The implementation of input validation frameworks and regular security testing can help prevent similar vulnerabilities from emerging in future development cycles. Organizations should also consider implementing web application firewalls or similar protective measures that can detect and block suspicious header injection attempts, providing an additional layer of defense beyond the application-level fixes.