CVE-2025-31695 in Link Field Display Mode Formatter
Summary
by MITRE • 04/01/2025
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Drupal Link field display mode formatter allows Cross-Site Scripting (XSS).This issue affects Link field display mode formatter: from 0.0.0 before 1.6.0.
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Analysis
by VulDB Data Team • 09/02/2025
This vulnerability represents a classic cross-site scripting flaw that exploits improper input sanitization within Drupal's link field display mode formatter component. The issue manifests when user-provided data containing malicious script code is processed and rendered in web page contexts without adequate neutralization. Attackers can leverage this weakness to inject malicious JavaScript code into web pages that are subsequently delivered to unsuspecting users. The vulnerability specifically impacts versions prior to 1.6.0 of the Drupal Link field display mode formatter, indicating that the developers identified and patched this particular code path where input validation was insufficient. This type of vulnerability falls under the CWE-79 category for cross-site scripting, which is one of the most prevalent and dangerous web application security flaws. The attack vector involves the manipulation of link field display logic where user-supplied URLs or link text are not properly escaped before being rendered in HTML contexts, creating opportunities for malicious code execution.
The technical implementation of this vulnerability occurs at the point where link field data is processed for display purposes within Drupal's content management framework. When administrators or users create links with potentially malicious content in either the URL or link text fields, the formatter fails to apply proper HTML escaping mechanisms before incorporating this data into generated web pages. This failure allows attackers to embed script tags, event handlers, or other malicious code sequences that execute in the context of other users' browsers when they view pages containing the compromised link data. The impact is particularly concerning in Drupal environments where multiple users interact with content management systems and where link fields are frequently used throughout various content types and display modes. The vulnerability demonstrates poor input validation practices and highlights the critical importance of context-aware sanitization in web applications. This flaw can be exploited through various attack scenarios including persistent XSS where malicious code is stored on the server and served to multiple users, or reflected XSS where the malicious payload is delivered through crafted URLs or form submissions.
The operational impact of CVE-2025-31695 extends beyond simple data corruption or unauthorized access to potentially enable full session hijacking, data theft, and malicious redirection attacks. When exploited successfully, this vulnerability allows attackers to execute arbitrary JavaScript code within the victim's browser context, potentially leading to complete compromise of user sessions and access to sensitive information. The attack can be particularly devastating in enterprise environments where Drupal systems manage sensitive content and user data. Users may be redirected to malicious websites, have their credentials stolen, or experience complete loss of browser-based application functionality. The vulnerability's persistence depends on whether the malicious input is stored in the system or requires continuous exploitation through crafted requests. This XSS vulnerability can also serve as a stepping stone for more sophisticated attacks, enabling attackers to establish persistent access through techniques such as cookie theft or browser fingerprinting. Organizations using affected versions of the Drupal Link field display mode formatter face significant risk exposure, particularly in environments where content creators have elevated privileges or where the application handles sensitive user information.
Mitigation strategies for this vulnerability require immediate patching to version 1.6.0 or later where the developers have implemented proper input sanitization and HTML escaping mechanisms. Organizations should conduct comprehensive vulnerability assessments to identify all instances of the affected component within their Drupal installations and ensure complete remediation. Additional protective measures include implementing content security policies that restrict script execution, deploying web application firewalls to detect and block malicious payloads, and establishing strict input validation procedures for all user-supplied content. Security teams should also consider implementing automated monitoring for suspicious content submissions and regular security audits of web application components. The fix implemented by Drupal developers addresses the root cause by ensuring that all user-provided data is properly escaped before being incorporated into HTML output, following established security best practices. Organizations should also review their overall XSS prevention strategies and ensure that all web application components follow consistent input sanitization protocols. This vulnerability underscores the critical importance of maintaining up-to-date software versions and implementing comprehensive security controls throughout the application lifecycle. The remediation process should include thorough testing to ensure that the patch does not introduce regressions in functionality while effectively addressing the XSS vulnerability.