CVE-2019-16532 in YzmCMS
Summary
by MITRE
An HTTP Host header injection vulnerability exists in YzmCMS V5.3. A malicious user can poison a web cache or trigger redirections.
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Analysis
by VulDB Data Team • 09/10/2020
The vulnerability identified as CVE-2019-16532 represents a critical HTTP Host header injection flaw within YzmCMS version 5.3, classified under CWE-640 Weak Server-Side Header Validation. This vulnerability stems from the application's insufficient validation of the Host header in HTTP requests, allowing attackers to manipulate this header field during web requests. The Host header is a critical component in HTTP/1.1 requests that specifies the domain name of the server to which the request is being sent, and when improperly validated, it can be exploited to inject malicious content or manipulate server behavior.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious HTTP request with a manipulated Host header value that bypasses the application's input validation mechanisms. This injection allows the attacker to poison web caches by injecting malicious content that gets stored in cache servers, or to trigger unauthorized redirections within the web application. The flaw essentially enables attackers to manipulate how the application processes and responds to incoming requests, potentially leading to various downstream attacks including cache poisoning, cross-site scripting, or web cache deception attacks.
From an operational perspective, this vulnerability poses significant risks to organizations using YzmCMS V5.3 as it can be exploited to redirect users to malicious websites, inject malicious content into cached responses, or manipulate application behavior to serve inappropriate content. The impact extends beyond simple redirection as it can compromise the integrity of web caches and potentially lead to more sophisticated attacks such as man-in-the-middle scenarios or session hijacking. Attackers can leverage this vulnerability to manipulate the application's response handling logic, potentially causing unauthorized access to sensitive resources or data exposure.
The exploitation of CVE-2019-16532 aligns with several ATT&CK techniques including T1566.001 for Phishing and T1071.004 for Application Layer Protocol. Organizations should implement immediate mitigations including strict validation of Host headers, implementing proper input sanitization mechanisms, and deploying web application firewalls to filter malicious header values. Additionally, regular security updates and patches should be applied to ensure that the CMS remains protected against known vulnerabilities. The vulnerability also highlights the importance of following secure coding practices that emphasize proper header validation and input sanitization as outlined in OWASP Top 10 security guidelines. Organizations should also consider implementing Content Security Policy headers and monitoring for unusual header values to detect potential exploitation attempts.