CVE-2015-5355 in GetSimple
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in GetSimple CMS before 3.3.6 allow remote attackers to inject arbitrary web script or HTML via the (1) post-content or (2) post-title parameter to admin/edit.php.
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Analysis
by VulDB Data Team • 05/22/2022
The vulnerability identified as CVE-2015-5355 represents a critical cross-site scripting flaw within GetSimple CMS versions prior to 3.3.6, exposing the platform to remote code execution risks through malicious web script injection. This vulnerability specifically affects the administrative editing functionality where user inputs are not properly sanitized before being rendered back to users, creating an exploitable condition that enables attackers to inject malicious payloads into the content management system's interface.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding mechanisms within the admin/edit.php script. Attackers can manipulate the post-content and post-title parameters through HTTP requests to inject malicious javascript code or HTML elements directly into the CMS's administrative interface. This flaw operates under CWE-79 which classifies Cross-Site Scripting vulnerabilities as weaknesses in input validation and output encoding, where the application fails to properly sanitize user-supplied data before incorporating it into dynamically generated web pages. The vulnerability exists because the system does not adequately escape or filter special characters that could be interpreted as HTML or script tags by web browsers.
The operational impact of CVE-2015-5355 extends beyond simple data theft or defacement, as successful exploitation could enable attackers to hijack administrator sessions, execute arbitrary commands on the server, or establish persistent backdoors within the CMS environment. When administrators access the compromised pages, their browsers execute the injected scripts, potentially leading to full system compromise. This vulnerability aligns with ATT&CK technique T1566 which describes social engineering attacks through malicious web content, and T1059 which covers command and scripting interpreter techniques. The attack surface is particularly concerning because it targets the administrative interface where privileged users interact with the system, potentially allowing attackers to gain elevated privileges and control over the entire content management platform.
Mitigation strategies for CVE-2015-5355 require immediate patching of GetSimple CMS to version 3.3.6 or later, which includes proper input sanitization and output encoding mechanisms. Organizations should implement comprehensive input validation that filters or escapes special characters such as angle brackets, quotes, and script tags before processing user content. Additionally, web application firewalls should be configured to detect and block suspicious payloads targeting these specific parameters. Regular security audits and penetration testing should verify that all input fields are properly sanitized, and administrators should be educated about the risks of clicking on suspicious links or visiting compromised websites. The remediation process should also include monitoring for any signs of exploitation, such as unauthorized content modifications or unexpected user activity within the CMS administrative interface.