CVE-2021-36668 in inSync
Summary
by MITRE • 07/12/2022
URL injection in Driva inSync 6.9.0 for MacOS, allows attackers to force a visit to an arbitrary url via the port parameter to the Electron App.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 07/07/2026
The vulnerability CVE-2021-36668 represents a critical url injection flaw in Driva inSync 6.9.0 for MacOS systems that leverages the Electron application framework's handling of URL parameters. This vulnerability specifically targets the port parameter within the application's URL parsing mechanism, allowing malicious actors to inject arbitrary URLs that will be automatically visited by the Electron-based application. The issue stems from insufficient input validation and sanitization of URL parameters, creating a path traversal and command injection vector that could be exploited to redirect users to malicious websites or execute unauthorized network requests. The Electron framework's default behavior of processing URL schemes and parameters without proper validation creates an attack surface where user-controllable input can influence the application's navigation flow.
The technical implementation of this vulnerability involves the Electron application's inability to properly sanitize or validate the port parameter in URL strings passed to the application. When a user interacts with inSync 6.9.0 on MacOS, if a specially crafted URL containing a malicious port parameter is processed, the application will interpret this input as a legitimate navigation instruction rather than a malicious payload. This flaw operates at the application layer where URL parsing occurs, bypassing typical network-level security controls and sandboxing mechanisms. The vulnerability is particularly concerning because it leverages the Electron framework's built-in URL handling capabilities without proper security boundaries, allowing attackers to manipulate the application's intended behavior through carefully crafted input parameters.
The operational impact of CVE-2021-36668 extends beyond simple redirection attacks, potentially enabling more sophisticated social engineering campaigns and phishing operations. Attackers could exploit this vulnerability to redirect users to malicious websites that appear legitimate, potentially harvesting credentials or sensitive information from unsuspecting users. The attack vector requires minimal user interaction as the vulnerability can be triggered through various means including crafted email links, malicious website content, or even through compromised network services that interact with the inSync application. This makes the vulnerability particularly dangerous in enterprise environments where users may be less security-aware and where the application's legitimate use cases could be leveraged to deliver malicious payloads. The vulnerability also represents a significant risk to data confidentiality and integrity as it could enable attackers to exfiltrate data or inject malicious content through the compromised application.
Mitigation strategies for CVE-2021-36668 should focus on immediate application updates from Driva to address the URL injection flaw, combined with network-level controls to prevent unauthorized access to the inSync application. Organizations should implement strict input validation policies at all application entry points, particularly for URL parameters and network configuration inputs. The vulnerability aligns with CWE-79 which describes improper neutralization of special elements in output used by a downstream component, and may map to ATT&CK techniques such as T1566 for social engineering and T1071 for application layer protocol usage. Network segmentation and firewall rules should be implemented to restrict access to the inSync application to trusted networks only, while endpoint detection and response solutions should be configured to monitor for unusual URL access patterns or network connections initiated by the application. Additionally, user education programs should emphasize the importance of verifying URL authenticity and avoiding suspicious links, as the vulnerability's exploitation often relies on user interaction with malicious content.