CVE-2015-2667 in GNS3
Summary
by MITRE
Untrusted search path vulnerability in GNS3 before 1.2.3 allows local users to gain privileges via a Trojan horse uuid.dll in an unspecified directory.
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Analysis
by VulDB Data Team • 06/30/2017
The vulnerability identified as CVE-2015-2667 represents a critical untrusted search path issue within GNS3 versions prior to 1.2.3, creating a significant security risk for local users. This flaw stems from the software's improper handling of dynamic library loading mechanisms, specifically when searching for the uuid.dll component. The vulnerability allows an attacker with local access to manipulate the system's library search order by placing a malicious Trojan horse uuid.dll file in an unspecified directory that gets prioritized during the loading process. This type of vulnerability falls under the CWE-427 category of Uncontrolled Search Path Element, where the application's search path is not properly validated or controlled, enabling attackers to inject malicious code. The issue is particularly concerning because it leverages the Windows dynamic linking mechanism, where the system searches for required libraries in a specific order including the current working directory, which can be manipulated by local users. The attack vector requires local system access, making it a local privilege escalation vulnerability that can be exploited by users who already have access to the system but lack administrative privileges.
The technical exploitation of this vulnerability involves understanding how Windows resolves dynamic library dependencies and how GNS3's implementation fails to properly secure this resolution process. When GNS3 attempts to load the uuid.dll library, it follows the standard Windows library search order which includes the current working directory, system directories, and paths specified in the PATH environment variable. An attacker can place a malicious uuid.dll file in a directory that appears earlier in this search order, causing the system to load the malicious version instead of the legitimate one. This creates a privilege escalation scenario where the malicious code executes with the privileges of the user running GNS3, potentially allowing for elevation to higher privileges if the application is running with elevated permissions. The vulnerability demonstrates poor security practices in library loading and path resolution that can be classified under the ATT&CK technique T1068 for Local Privilege Escalation, where adversaries leverage flaws in application behavior to gain elevated system access.
The operational impact of CVE-2015-2667 extends beyond simple local privilege escalation, as it represents a fundamental flaw in how the application manages its runtime dependencies and can potentially lead to more severe consequences. Organizations using affected versions of GNS3 face significant risk because the vulnerability can be exploited by any local user, including malicious insiders or compromised accounts. The attack requires minimal sophistication and can be automated, making it particularly dangerous in environments where multiple users have local access to systems running vulnerable versions of the software. The vulnerability affects network simulation and emulation environments where GNS3 is commonly deployed, potentially compromising entire network infrastructure testing environments. Security professionals should note that this vulnerability aligns with the principle of least privilege violations, where applications fail to properly isolate their execution environment from potentially malicious inputs. The impact is amplified because GNS3 is often used in educational and enterprise environments where users may have elevated access rights, increasing the potential for damage if the vulnerability is successfully exploited. Remediation efforts should focus on updating to GNS3 version 1.2.3 or later, which implements proper library loading mechanisms and validates search paths to prevent unauthorized library injection attacks.
The broader implications of this vulnerability highlight the importance of secure coding practices and proper library management in application development. This issue demonstrates how seemingly simple library loading mechanisms can create significant security holes when not properly implemented with security considerations. The vulnerability serves as a reminder of the critical need for developers to follow secure coding guidelines and implement proper input validation and path resolution controls. Organizations should implement comprehensive patch management procedures to ensure that vulnerable software components are updated promptly. The incident also underscores the necessity of conducting security reviews of third-party applications and their dependency management practices. From a compliance perspective, this vulnerability could potentially violate security standards such as those outlined in ISO 27001, which requires organizations to maintain secure system configurations and address known vulnerabilities. The security community should view this vulnerability as an example of how local privilege escalation flaws can be exploited in real-world scenarios, particularly in environments where multiple users share systems or where privilege separation is not properly enforced.