CVE-2023-31045 in Backdrop
Summary
by MITRE • 04/24/2023
A stored Cross-site scripting (XSS) issue in Text Editors and Formats in Backdrop CMS before 1.24.2 allows remote attackers to inject arbitrary web script or HTML via the name parameter. When a user is editing any content type (e.g., page, post, or card) as an admin, the stored XSS payload is executed upon selecting a malicious text formatting option. NOTE: the vendor disputes the security relevance of this finding because "any administrator that can configure a text format could easily allow Full HTML anywhere."
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Analysis
by VulDB Data Team • 04/06/2026
The vulnerability CVE-2023-31045 represents a stored cross-site scripting flaw within the Text Editors and Formats module of Backdrop CMS versions prior to 1.24.2. This issue arises from insufficient input validation and sanitization of the name parameter when administrators configure text formatting options for content types. The flaw allows remote attackers to inject malicious scripts that persist in the system and execute when users interact with content containing the compromised formatting settings.
The technical implementation of this vulnerability occurs within the content editing interface where administrators can define text formats for different content types such as pages, posts, or cards. When a malicious actor crafts a specially formatted name parameter containing XSS payloads and saves it as part of a text format configuration, the payload becomes stored within the CMS database. Upon subsequent content editing sessions, particularly when administrators select the compromised text formatting option, the stored script executes in the browser context of any user who interacts with that content, creating a persistent XSS vector.
This vulnerability operates under the Common Weakness Enumeration CWE-79 category, specifically addressing stored cross-site scripting weaknesses where user-controllable data is incorporated into web pages without proper validation or sanitization. The attack surface is particularly concerning as it targets administrative interfaces where privileged users have elevated permissions to configure system settings. The exploit requires minimal privileges to set up the initial payload, making it a significant risk for environments where multiple administrators have access to text format configuration capabilities.
The operational impact of this vulnerability extends beyond simple script execution as it can enable attackers to escalate privileges, steal session cookies, perform actions on behalf of authenticated users, and potentially gain access to sensitive administrative functions. The vendor's position that this vulnerability lacks security relevance due to administrative access requirements is problematic because it overlooks the fact that many organizations have multiple administrators with varying levels of trust and security awareness. Additionally, the compromise of a single administrator account can provide attackers with extensive control over the entire content management system.
The exploitation scenario involves an attacker first gaining access to a privileged administrative account or finding a way to manipulate the text format configuration process. Once the malicious payload is stored, it executes automatically whenever any user with appropriate permissions views or edits content using the compromised formatting option. This makes the vulnerability particularly dangerous in multi-user environments where administrators regularly edit content and interact with various text formatting options. The persistence of the vulnerability means that even after initial exploitation, the malicious code continues to execute until the affected text format is removed or modified.
Organizations should implement immediate mitigations including updating to Backdrop CMS version 1.24.2 or later, which includes proper input sanitization and validation for the affected parameters. Additional protective measures involve restricting administrative access to text format configuration to only trusted users, implementing content security policies, and conducting regular security audits of all administrative interfaces. The vulnerability highlights the importance of validating and sanitizing all user inputs in web applications, particularly within administrative interfaces where the potential for privilege escalation exists. Security monitoring should include detection of unusual text format configurations and automated scanning for stored XSS vulnerabilities in content management systems to prevent exploitation of similar issues in the future.