CVE-2023-3540 in NewsLetter Script PHP
Summary
by MITRE • 07/07/2023
A vulnerability, which was classified as problematic, was found in SimplePHPscripts NewsLetter Script PHP 2.4. Affected is an unknown function of the file /preview.php of the component URL Parameter Handler. The manipulation leads to cross site scripting. It is possible to launch the attack remotely. The identifier of this vulnerability is VDB-233292.
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Analysis
by VulDB Data Team • 07/25/2023
The vulnerability identified as CVE-2023-3540 represents a critical cross site scripting flaw within the SimplePHPscripts NewsLetter Script PHP version 2.4. This security weakness resides in the URL Parameter Handler component, specifically within the /preview.php file, making it susceptible to exploitation through web-based attack vectors. The vulnerability's classification as problematic indicates significant security implications that could compromise user sessions and data integrity. The issue manifests when user-supplied input parameters are not properly sanitized before being processed and rendered back to users, creating an environment where malicious scripts can be executed within the context of other users' browsers.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding practices within the newsletter script's preview functionality. When the application processes URL parameters through the preview.php endpoint, it fails to adequately sanitize or escape user-provided data before incorporating it into dynamic web content. This oversight allows attackers to inject malicious javascript code through crafted URL parameters that are then executed in the victim's browser when the preview page is rendered. The vulnerability operates under CWE-79 which specifically addresses cross site scripting flaws in web applications, where improper validation of input data leads to execution of unauthorized code. The attack can be initiated remotely without requiring any local privileges or user interaction beyond accessing the vulnerable web application, making it particularly dangerous for widespread exploitation.
The operational impact of CVE-2023-3540 extends beyond simple script execution, potentially enabling attackers to hijack user sessions, steal sensitive information, modify content, or redirect users to malicious websites. Given that this vulnerability affects a newsletter script, successful exploitation could allow attackers to access subscriber data, manipulate newsletter content, or even use the compromised system as a launchpad for further attacks against the broader network infrastructure. The remote exploitation capability means that attackers can target users from any location without requiring physical access to the system, significantly expanding the potential attack surface. This vulnerability directly aligns with attack techniques described in the ATT&CK framework under T1566 which covers social engineering methods including the use of malicious links and payloads that leverage web application vulnerabilities.
Mitigation strategies for this vulnerability should prioritize immediate implementation of input validation and output encoding measures within the preview.php component. The most effective approach involves sanitizing all user-provided parameters through proper escaping techniques before rendering them in web pages, specifically implementing context-appropriate encoding for html, javascript, and url contexts. Additionally, implementing a content security policy can provide additional protection against script execution, while regular security audits and input validation testing should be conducted to identify similar vulnerabilities. The affected SimplePHPscripts NewsLetter Script PHP version 2.4 should be updated to the latest available version that contains patches addressing this specific vulnerability, as vendor-provided updates typically include proper parameter validation and sanitization mechanisms. Organizations should also consider implementing web application firewalls to detect and block malicious requests targeting this specific vulnerability pattern, while establishing monitoring procedures to detect unusual traffic patterns that might indicate exploitation attempts against the newsletter system.