CVE-2018-17077 in yiqicms
Summary
by MITRE
An issue was discovered in yiqicms through 2016-11-20. There is stored XSS in comment.php because a length limit can be bypassed.
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Analysis
by VulDB Data Team • 03/24/2020
The vulnerability identified as CVE-2018-17077 represents a critical stored cross-site scripting flaw within the yiqicms content management system version 2016-11-20 and earlier. This vulnerability resides in the comment.php component where user input is processed and stored without adequate sanitization measures. The flaw stems from an insufficient validation mechanism that allows malicious actors to inject malicious scripts into comment fields, which are then executed whenever other users view these comments. The vulnerability specifically exploits a length limitation bypass technique that enables attackers to submit payloads exceeding the intended input constraints, thereby circumventing the system's protective measures.
The technical implementation of this vulnerability aligns with CWE-79 which classifies cross-site scripting as a weakness where untrusted data is incorporated into web pages without proper validation or encoding. This stored XSS vulnerability operates by allowing attackers to inject malicious JavaScript code into the comment submission process. When legitimate users access pages containing these compromised comments, their browsers execute the malicious scripts within their security context, potentially leading to session hijacking, credential theft, or further exploitation of the victim's browser. The bypass mechanism for the length limitation suggests that the system employs a simple character count check rather than robust input validation, making it susceptible to manipulation through various encoding techniques or payload obfuscation methods.
The operational impact of this vulnerability extends beyond simple data corruption or display issues. Attackers can leverage this flaw to perform session fixation attacks, steal user cookies, redirect victims to malicious domains, or inject additional malicious content that could compromise the entire website. The stored nature of the vulnerability means that once a malicious comment is submitted and saved to the database, it continues to affect users until manually removed. This persistent threat can lead to prolonged unauthorized access to user accounts, data exfiltration, and potential compromise of the entire content management system infrastructure. The vulnerability particularly affects websites using yiqicms that rely on user-generated content through comment features, making it a significant concern for blogs, forums, and content-heavy websites.
Mitigation strategies for this vulnerability should include immediate implementation of proper input sanitization and output encoding mechanisms throughout the comment processing pipeline. The system must enforce strict validation of all user inputs, including length restrictions that cannot be bypassed through simple manipulation techniques. Security measures should incorporate the principle of least privilege by ensuring that comment submissions are properly filtered and encoded before storage. Organizations should implement Content Security Policy headers to limit script execution and consider using Web Application Firewalls to detect and block malicious payloads. Regular security audits and code reviews should be conducted to identify similar vulnerabilities in other components of the system. The remediation process must also include immediate patching of the yiqicms installation and potentially implementing additional monitoring mechanisms to detect unauthorized comment submissions. According to ATT&CK framework, this vulnerability maps to T1059.007 for script injection and T1566 for social engineering techniques that could exploit this flaw to compromise user sessions. The vulnerability demonstrates the critical importance of proper input validation and the potential consequences of insufficient security controls in web applications, particularly those handling user-generated content.