CVE-2010-3927 in Lunascape
Summary
by MITRE
Untrusted search path vulnerability in Lunascape before 6.4.0 allows local users to gain privileges via a Trojan horse DLL in the current working directory.
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Analysis
by VulDB Data Team • 02/08/2019
The vulnerability identified as CVE-2010-3927 represents a critical untrusted search path issue affecting Lunascape web browsers prior to version 6.4.0. This flaw resides in the application's dynamic link library loading mechanism, where the software fails to properly validate the source and integrity of dynamically loaded libraries. The vulnerability manifests when the browser attempts to load necessary DLL components and inadvertently loads malicious code from the current working directory instead of the intended secure locations. This type of vulnerability falls under the CWE-427 category, which specifically addresses uncontrolled search path dependencies where applications use untrusted paths to load dynamic libraries, creating a pathway for privilege escalation attacks.
The technical exploitation of this vulnerability occurs through a Trojan horse DLL attack vector where a local malicious actor places a specially crafted malicious DLL file in the same directory as the Lunascape executable or in the current working directory from which the application is launched. When the browser processes certain operations requiring dynamic library loading, it automatically loads the malicious DLL from the untrusted search path rather than from the legitimate system directories. This behavior leverages the Windows DLL search order mechanism, which first searches the current working directory before examining system directories, thereby enabling the attacker to execute arbitrary code with the privileges of the victim user. The vulnerability directly aligns with ATT&CK technique T1059.001 for execution through command and scripting interpreter and T1546.009 for exploitation of system services through DLL side-loading.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential full system compromise when combined with other attack vectors. Local users who can write to the directory containing the vulnerable browser executable can effectively gain elevated privileges without requiring administrative credentials. This creates a significant risk for environments where users have local access to systems running affected browser versions, particularly in corporate settings where users may have standard user privileges but need to run browser applications. The vulnerability is particularly dangerous because it requires minimal user interaction to exploit and can be combined with social engineering techniques to deliver the malicious DLL payload. Additionally, the persistence aspect of this vulnerability means that once exploited, attackers can maintain access through the elevated privileges gained, potentially allowing for data exfiltration, system reconnaissance, or further lateral movement within the network. Organizations running vulnerable versions of Lunascape should immediately implement patch management procedures to upgrade to version 6.4.0 or later, while also implementing additional security controls such as application whitelisting, directory permission controls, and monitoring for suspicious DLL loading activities to prevent exploitation of this and similar vulnerabilities.