CVE-2026-118561 in Single Content Sync Plugin
Summary
by MITRE • 10/30/2026
External Control of File Name or Path vulnerability in Drupal Single Content Sync allows Path Traversal. This issue affects Single Content Sync versions: from 0.0.0 to 1.4.19.
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified as External Control of File Name or Path within the Drupal module Single Content Sync represents a critical security flaw that enables path traversal attacks. This specific weakness arises when the application accepts user-supplied input for file paths without adequately sanitizing or validating those inputs against expected directory structures. In versions ranging from 0.0.0 to 1.4.19, the mechanism responsible for synchronizing content fails to properly restrict access to files located outside of designated safe directories. This lack of rigorous validation allows an attacker to manipulate file path parameters by injecting special characters such as dot-dot-slash sequences or absolute paths, thereby bypassing intended security boundaries and accessing arbitrary files on the underlying server filesystem.
From a technical perspective, this flaw aligns with CWE-22, which defines Improper Limitation of a Pathname to a Restricted Directory. The core issue lies in the failure to canonicalize user input before processing it or failing to ensure that the resolved path remains within an allowed base directory. When Single Content Sync processes synchronization requests, it likely constructs file paths using unsanitized variables derived from HTTP parameters or configuration inputs. If these inputs contain traversal sequences, the operating system resolves them relative to the current working directory rather than restricting access to a specific sandboxed area. This behavior permits reading sensitive files such as configuration files containing database credentials, private keys, or other application secrets that reside in parent directories above the web root.
The operational impact of this vulnerability is severe, particularly for Drupal sites relying on Single Content Sync for managing content across environments. An authenticated attacker with sufficient privileges to trigger synchronization operations can exploit this flaw to read arbitrary files from the server. This capability facilitates unauthorized data disclosure and can serve as a stepping stone for further exploitation. For instance, access to configuration files may reveal database connection strings or API keys, which could be leveraged to compromise backend systems. Additionally, if write permissions are misconfigured in conjunction with other vulnerabilities, this path traversal could potentially lead to remote code execution by overwriting critical system files or web shells, although the primary risk described is information disclosure through file inclusion and reading capabilities.
This vulnerability maps directly to several tactics within the MITRE ATT&CK framework. It corresponds to Tactic TA0006, Credential Access, specifically under techniques like T1530 Data from Local System, as attackers can dump sensitive configuration data. Furthermore, it relates to Discovery techniques such as T1083 File and Directory Discovery, where adversaries probe the file system structure to identify valuable targets for subsequent attacks. The exploitation of this flaw does not require complex payload construction beyond standard path traversal strings but relies on precise timing and access rights within the Drupal environment, making it a high-risk issue that demands immediate attention given its prevalence in older versions of the module.
Mitigation strategies must focus on both upgrading the software and implementing defensive coding practices. The primary remediation is to upgrade Single Content Sync to version 1.4.20 or later, where this vulnerability has been addressed by developers through improved input validation and path canonicalization checks. For organizations unable to immediately patch due to compatibility constraints, temporary mitigations should include restricting file system permissions so that the web server process cannot read files outside of its designated document root. Additionally, implementing a Web Application Firewall with rulesets capable of detecting and blocking common path traversal patterns can provide an additional layer of defense. Developers reviewing custom code or integrations involving this module should ensure that all file paths are resolved to their absolute canonical forms and verified against a whitelist of allowed directories before any I/O operations are performed. Regular security audits and static application security testing focused on CWE-22 scenarios will help prevent similar issues in future development cycles.