CVE-2018-7653 in YzmCMS
Summary
by MITRE
In YzmCMS 3.6, index.php has XSS via the a, c, or m parameter.
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Analysis
by VulDB Data Team • 08/26/2025
The vulnerability identified as CVE-2018-7653 affects YzmCMS version 3.6 and represents a cross-site scripting flaw located in the index.php file. This issue arises from insufficient input validation and sanitization of parameters within the web application's request handling mechanism. The vulnerability specifically impacts the a, c, and m parameters, which are commonly used in content management systems to define actions, controllers, and modules respectively. These parameters are processed without adequate filtering or encoding, creating an avenue for malicious actors to inject malicious scripts into the application's response.
The technical nature of this vulnerability aligns with CWE-79 which categorizes cross-site scripting flaws as weaknesses in web applications where untrusted data is incorporated into web pages without proper validation or encoding. The flaw exists because the application fails to implement proper input sanitization techniques before incorporating user-supplied parameters into the HTTP response. When these parameters are directly reflected in the page output without appropriate HTML entity encoding or other protective measures, attackers can craft malicious payloads that execute within the context of other users' browsers. This type of vulnerability is particularly dangerous because it can be exploited to hijack user sessions, steal sensitive information, or perform unauthorized actions on behalf of victims.
The operational impact of this vulnerability is significant as it allows attackers to execute arbitrary JavaScript code in the victim's browser context. An attacker could potentially redirect users to malicious websites, steal authentication cookies, or modify the functionality of the web application. The vulnerability affects the core functionality of the content management system and could compromise the entire application if exploited successfully. Given that CMS platforms often contain sensitive administrative interfaces and user data, this vulnerability could provide attackers with a foothold for further exploitation within the affected environment.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and output encoding mechanisms. The recommended approach involves sanitizing all user-supplied parameters before they are processed or rendered in web responses. This includes implementing proper HTML entity encoding for any data that is reflected back to users, as well as employing strict input validation to reject or filter out potentially malicious content. Additionally, developers should implement Content Security Policy headers to limit the execution of unauthorized scripts. The fix should also include updating the application to a patched version if available, as this vulnerability was likely addressed in subsequent releases. Organizations should also consider implementing web application firewalls to detect and prevent exploitation attempts, while maintaining proper logging and monitoring to identify potential exploitation activities. This vulnerability demonstrates the critical importance of secure coding practices and input validation in web applications, particularly those handling user-supplied data through URL parameters. The issue is classified under the ATT&CK framework as part of the web application exploitation techniques, specifically targeting the execution of malicious code through input manipulation.