CVE-2017-20035 in PHPList
Summary
by MITRE • 06/10/2022
A vulnerability, which was classified as problematic, has been found in PHPList 3.2.6. This issue affects some unknown processing of the file /lists/admin/ of the component Subscribe. The manipulation leads to cross site scripting (Persistent). The attack may be initiated remotely. Upgrading to version 3.3.1 is able to address this issue. It is recommended to upgrade the affected component.
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Analysis
by VulDB Data Team • 11/22/2022
This vulnerability in PHPList 3.2.6 represents a persistent cross site scripting flaw that resides within the Subscribe component of the application's administrative interface. The issue manifests in the file processing logic located at /lists/admin/ which handles user subscription functionalities. The vulnerability classification as problematic indicates the severity of potential impact on system security and user data integrity. The flaw occurs during the processing of user input within the subscription handling mechanism, creating a persistent XSS vector that can affect multiple users who interact with the compromised system. The attack vector is remotely exploitable, meaning malicious actors can initiate the vulnerability without requiring physical access to the system or direct user interaction beyond visiting the affected page. This remote exploit capability significantly amplifies the potential impact as attackers can compromise users simply by directing them to maliciously crafted URLs or embedding malicious content within the vulnerable subscription forms.
The technical implementation of this vulnerability stems from inadequate input validation and output sanitization within the administrative subscription processing code. When users submit subscription data through the affected interface, the application fails to properly sanitize or escape user-provided content before storing it in a persistent manner. This allows attackers to inject malicious javascript code into the subscription records, which then gets executed whenever other administrators or users view the affected subscription data. The persistent nature of this vulnerability means that the malicious code remains embedded in the system even after the initial attack, continuously executing whenever the compromised data is rendered or processed. This characteristic aligns with CWE-79, which specifically addresses cross site scripting vulnerabilities where insufficient validation of input data leads to code execution in the victim's browser context. The vulnerability operates at the application layer and can potentially be leveraged to escalate privileges, steal session cookies, or redirect users to malicious sites.
The operational impact of this vulnerability extends beyond simple data corruption or display issues. Attackers can exploit this persistent XSS to gain unauthorized access to administrative functions, steal sensitive information from user accounts, or manipulate subscription data to conduct further attacks. The remote exploit capability allows for large-scale compromise of multiple users who interact with the vulnerable system, potentially affecting thousands of subscribers depending on the size of the mailing list. The vulnerability affects the core subscription functionality of PHPList, which is critical for email marketing operations, making it particularly dangerous for organizations that rely heavily on email communications. This vulnerability can be exploited to conduct session hijacking attacks, where attackers steal authentication tokens and impersonate legitimate users within the system. The impact is further compounded by the fact that administrators may unknowingly interact with the malicious content while managing subscriptions, providing attackers with elevated privileges and access to sensitive administrative functions.
The recommended remediation approach involves upgrading the affected PHPList installation to version 3.3.1 or later, which contains the necessary patches to address the input validation and output sanitization issues. Organizations should implement a comprehensive patch management strategy that includes regular security updates and vulnerability assessments to prevent similar issues from occurring in the future. Additional mitigations include implementing proper input validation at multiple layers of the application, including server-side validation and output encoding for all user-provided content. Security measures should also include regular security audits of web applications, implementation of content security policies to prevent unauthorized script execution, and monitoring of user-submitted data for suspicious patterns. Organizations should also consider implementing web application firewalls to detect and block malicious requests targeting known XSS vulnerabilities. The vulnerability demonstrates the importance of proper security testing during application development and the necessity of maintaining up-to-date security patches to protect against known exploitation techniques. This case highlights the critical need for organizations to maintain robust security practices and stay informed about emerging threats that could compromise their web applications and user data.