CVE-2020-27409 in Community Edition
Summary
by MITRE • 12/04/2020
OpenSIS Community Edition before 7.5 is affected by a cross-site scripting (XSS) vulnerability in SideForStudent.php via the modname parameter.
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Analysis
by VulDB Data Team • 12/12/2020
The vulnerability identified as CVE-2020-27409 represents a critical cross-site scripting flaw within the OpenSIS Community Edition version 7.4 and earlier. This vulnerability exists in the SideForStudent.php script where user-supplied input through the modname parameter is not properly sanitized or validated before being rendered in the web application's output. The flaw allows malicious actors to inject arbitrary JavaScript code into web pages viewed by other users, potentially enabling session hijacking, credential theft, or further exploitation of the affected system. The vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws in web applications. This weakness creates a persistent security risk as it allows attackers to execute malicious scripts in the context of the victim's browser, bypassing normal security restrictions that protect user sessions and data.
The technical implementation of this vulnerability demonstrates a classic input validation failure where the modname parameter in SideForStudent.php fails to properly escape or filter user-provided data before incorporating it into dynamic web content. When a user navigates to a page with malicious content in the modname parameter, the web application processes this input without adequate sanitization measures, resulting in the execution of injected scripts within the victim's browser context. This flaw aligns with ATT&CK technique T1566 which describes social engineering attacks that leverage web-based vulnerabilities to compromise user systems. The vulnerability's impact extends beyond simple script execution as it can be leveraged to establish persistent access through session manipulation or to redirect users to malicious sites that can harvest sensitive information.
The operational implications of this vulnerability are significant for educational institutions using OpenSIS Community Edition, as it creates opportunities for unauthorized access to student records, academic data, and administrative functions. Attackers could exploit this vulnerability to gain unauthorized access to sensitive educational information, manipulate student grades, or disrupt normal academic operations. The vulnerability affects the integrity and confidentiality of the entire system, as any user with access to the affected application could potentially exploit this flaw. Organizations may face regulatory compliance issues if sensitive student data is compromised, particularly in environments governed by FERPA or similar educational data protection regulations. The persistent nature of XSS vulnerabilities means that once exploited, attackers can maintain access and continue to monitor or manipulate user sessions until the vulnerability is patched and the system is properly secured.
Organizations should immediately implement the vendor-provided patch for OpenSIS Community Edition version 7.5 which addresses this vulnerability through proper input sanitization and output encoding of the modname parameter. Additional mitigations include implementing comprehensive input validation at multiple layers of the application, deploying web application firewalls to detect and block malicious payloads, and conducting regular security assessments of web applications to identify similar vulnerabilities. The remediation process should include thorough testing of the patched version to ensure that all input parameters are properly sanitized and that no regression issues have been introduced. Security teams should also implement monitoring and logging mechanisms to detect potential exploitation attempts of this vulnerability. Organizations using older versions of OpenSIS should prioritize upgrading to the patched version and conduct comprehensive security reviews of their entire web application stack to identify and remediate similar input validation issues that may exist elsewhere in the system.