CVE-2017-12798 in NexusPHP
Summary
by MITRE
Cross-Site Scripting (XSS) exists in NexusPHP version v1.5 via the q parameter to searchsuggest.php.
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Analysis
by VulDB Data Team • 11/06/2019
The vulnerability CVE-2017-12798 represents a classic cross-site scripting flaw discovered in NexusPHP version v1.5, specifically within the searchsuggest.php script where the q parameter is processed. This type of vulnerability falls under CWE-79 which categorizes improper neutralization of input during web page generation, making it a critical concern for web application security. The flaw allows malicious actors to inject arbitrary JavaScript code into the web application's response, potentially compromising user sessions and enabling unauthorized actions.
The technical implementation of this vulnerability occurs when the q parameter passed to searchsuggest.php is not properly sanitized or escaped before being rendered in the web page output. This creates an opening for attackers to craft malicious payloads that execute within the context of other users' browsers. The vulnerability specifically affects the search functionality of the NexusPHP platform, where user input intended for search suggestions becomes a vector for code injection. When a victim visits a page containing the maliciously crafted search suggestion, the injected JavaScript executes in their browser, potentially stealing session cookies, redirecting to malicious sites, or performing actions on behalf of the user.
The operational impact of this vulnerability extends beyond simple data theft, as it enables attackers to establish persistent footholds within the application environment. Users who perform searches using the affected functionality become potential victims of session hijacking, credential theft, or redirection to phishing sites. The vulnerability's severity is amplified by the fact that it affects a core search functionality that is likely accessed frequently by users, increasing the attack surface and potential exposure. This type of vulnerability also aligns with ATT&CK technique T1531 which involves establishing persistence through the modification of application code or configuration files, as attackers could leverage XSS to inject malicious scripts that maintain access over time.
Mitigation strategies for CVE-2017-12798 should focus on implementing proper input validation and output encoding mechanisms. The primary defense involves sanitizing all user-supplied input through the q parameter before incorporating it into dynamic web content. This approach aligns with the principle of least privilege and input validation as outlined in OWASP Top Ten security practices. Organizations should implement proper HTML escaping or encoding of all dynamic content before rendering it in web pages, ensuring that any special characters are properly handled to prevent script execution. Additionally, deploying a web application firewall capable of detecting and blocking XSS attack patterns, along with regular security updates and patches to the NexusPHP platform, would provide comprehensive protection against this and similar vulnerabilities. The implementation of content security policies and proper session management practices further reduces the risk of exploitation.