CVE-2019-14770 in Backdrop
Summary
by MITRE
In Backdrop CMS 1.12.x before 1.12.8 and 1.13.x before 1.13.3, some menu links within the administration bar may be crafted to execute JavaScript when the administrator is logged in and uses the search functionality. (This issue is mitigated by the attacker needing permissions to create administrative menu links, such as by creating a content type or layout. Such permissions are usually restricted to trusted or administrative users.)
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Analysis
by VulDB Data Team • 11/21/2023
This vulnerability exists within Backdrop CMS versions prior to 1.12.8 and 1.13.3, representing a cross-site scripting flaw that specifically targets administrative users through the administration bar interface. The issue manifests when crafted menu links are created with malicious JavaScript payloads that execute when administrators interact with the search functionality. This represents a sophisticated attack vector that leverages the trust relationship between the CMS and its administrative users, exploiting the inherent privilege escalation potential within content management systems. The vulnerability falls under the category of CWE-79 Improper Neutralization of Input During Web Page Generation, which specifically addresses the failure to properly sanitize user-supplied input that gets reflected back to users in web pages.
The technical exploitation requires an attacker to possess permissions that allow creation of administrative menu links, typically through roles with content type creation or layout management capabilities. This prerequisite ensures that the vulnerability remains mitigated against casual attackers who lack appropriate administrative privileges, but still represents a significant risk within organizations where trusted users might be compromised. The attack occurs when administrators perform search operations within the administration bar, triggering the execution of malicious JavaScript code in the context of their privileged session. This creates a persistent threat vector that can lead to complete administrative compromise, as the executing JavaScript runs with the full privileges of the logged-in administrator.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it provides attackers with the capability to manipulate the CMS configuration, create or modify content, access sensitive administrative functions, and potentially establish persistent backdoors within the system. The attack chain requires the attacker to first gain sufficient permissions to create malicious menu links, then wait for an administrator to perform a search operation, making this a stealthy and potentially long-term threat. The vulnerability demonstrates the critical importance of input validation and output sanitization in web applications, particularly within privileged interfaces where the potential for damage is exponentially higher than in regular user-facing components.
Mitigation strategies should focus on immediate patching of affected versions, implementing strict access controls for menu link creation, and monitoring administrative user activities for suspicious patterns. Organizations should also consider implementing additional security layers such as content security policies to prevent script execution in administrative contexts, and regular security audits of administrative menu structures. The vulnerability highlights the need for principle of least privilege implementation, ensuring that administrative permissions are granted only to users who absolutely require them, and that all user-supplied content within privileged interfaces undergoes rigorous sanitization before being rendered to users. This aligns with ATT&CK technique T1078 Valid Accounts which emphasizes the importance of securing administrative access and preventing unauthorized privilege escalation through trusted user accounts.