CVE-2017-17778 in Paid To Read Script
Summary
by MITRE
Paid To Read Script 2.0.5 has XSS via the referrals.php tier parameter or the admin/userview.php uid parameter.
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Analysis
by VulDB Data Team • 12/16/2019
The vulnerability identified as CVE-2017-17778 affects the Paid To Read Script version 2.0.5, a web application designed for content monetization through reader engagement. This particular flaw represents a cross-site scripting vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. The vulnerability manifests through two distinct attack vectors within the application's codebase, specifically targeting the referrals.php page where the tier parameter is processed and the admin/userview.php page where the uid parameter is handled. Both parameters fail to properly sanitize user input before incorporating it into dynamic web page content, creating opportunities for malicious actors to execute unauthorized code within the context of other users' browsers.
The technical nature of this vulnerability aligns with CWE-79, which describes cross-site scripting flaws where untrusted data is incorporated into web pages without proper validation or encoding. The flaw occurs because the application does not implement adequate input sanitization mechanisms for the tier and uid parameters, allowing attackers to submit malicious payloads that get executed when legitimate users view the affected pages. This type of vulnerability typically arises from insufficient output encoding and improper validation of user-supplied data, which are fundamental security practices that should be implemented at every layer of web application development. The attack surface is particularly concerning as it affects both frontend user interfaces and backend administrative functions, potentially allowing attackers to escalate privileges or access sensitive user data.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform various malicious activities within the context of authenticated users. An attacker could potentially steal session cookies, redirect users to malicious websites, deface the application's content, or even gain access to administrative functions if the targeted users have elevated privileges. The vulnerability affects both regular users and administrators, making it particularly dangerous as it could be exploited to compromise the entire application ecosystem. When combined with other attack techniques, such as session hijacking or privilege escalation, this XSS vulnerability could result in complete system compromise and unauthorized access to user accounts and sensitive data.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and output encoding mechanisms throughout the application. The most effective approach involves sanitizing all user inputs through proper encoding before they are processed or displayed in web pages, specifically addressing the tier and uid parameters in the affected files. Implementing Content Security Policy headers can provide additional defense-in-depth measures by restricting the sources from which scripts can be loaded and executed within the application. Regular security code reviews and automated vulnerability scanning should be integrated into the development lifecycle to identify similar issues before they can be exploited. The application should also implement proper parameter validation and sanitization techniques that align with industry standards such as those recommended by the Open Web Application Security Project. Additionally, implementing proper access controls and privilege separation between user and administrative functions can limit the potential damage that could result from successful exploitation of this vulnerability.