CVE-2025-4532 in SunloginClient
Summary
by MITRE • 05/11/2025
A vulnerability classified as critical has been found in Shanghai Bairui Information Technology SunloginClient 15.8.3.19819. This affects an unknown part in the library process.dll of the file sunlogin_guard.exe. The manipulation leads to uncontrolled search path. Local access is required to approach this attack. The complexity of an attack is rather high. The exploitability is told to be difficult. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 05/11/2025
The vulnerability identified as CVE-2025-4532 represents a critical security flaw in the Shanghai Bairui Information Technology SunloginClient software version 15.8.3.19819. This issue manifests within the process.dll library component of the sunlogin_guard.exe file, creating a dangerous uncontrolled search path condition that can be exploited by malicious actors. The vulnerability requires local access to execute successfully, making it a local privilege escalation or lateral movement vector rather than a remote attack surface. The attack complexity is rated as high, indicating that successful exploitation demands specialized knowledge and resources that go beyond typical automated attack tools. This classification aligns with CWE-428 which describes "Uncontrolled Search Path Element" where an application searches for files or libraries in a manner that can be manipulated by an attacker to load malicious code.
The technical implementation of this vulnerability stems from improper handling of library search paths within the sunlogin_guard.exe process, specifically involving the process.dll component. When the application attempts to load dynamic link libraries, it follows a search order that can be manipulated by an attacker who has local access to the system. This creates an opportunity for attackers to place malicious DLL files in directories that are searched before legitimate system directories, effectively enabling code execution with the privileges of the targeted process. The uncontrolled search path vulnerability falls under the broader category of DLL hijacking attacks and can be mapped to ATT&CK technique T1036.003 which covers "Taint Shared Library". The exploitability difficulty rating reflects the need for local system access and the requirement to carefully position malicious files within the search path, making it more challenging than typical remote exploits but still potentially dangerous in environments where local access is possible.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to gain persistent access to systems running the affected SunloginClient software. The local access requirement means that attackers must first compromise a user's local system, potentially through social engineering, phishing, or other initial compromise techniques. Once local access is achieved, the vulnerability can be leveraged to execute arbitrary code with elevated privileges, potentially leading to complete system compromise. The fact that this vulnerability has been publicly disclosed and is believed to be in use underscores the urgency for affected organizations to implement immediate mitigations. The lack of vendor response to early disclosure attempts further compounds the risk, leaving organizations without official patches or updates to address the issue.
Organizations should immediately implement mitigations including disabling or removing the vulnerable SunloginClient software from systems where it is not essential, implementing strict file system permissions to prevent unauthorized DLL placement, and monitoring for suspicious file creation patterns in system directories. Network segmentation and least privilege access controls should be enforced to limit the potential impact of successful exploitation. System administrators should also conduct thorough audits of systems to identify all instances of the vulnerable software and ensure that appropriate security measures are in place. The vulnerability demonstrates the importance of proper library loading practices and the need for developers to implement secure coding practices that prevent uncontrolled search path conditions. Additionally, organizations should consider implementing application whitelisting solutions to prevent execution of unauthorized code, and should maintain current threat intelligence to monitor for indicators of compromise related to this specific vulnerability. The presence of public exploits for this vulnerability indicates that it may be actively targeted by threat actors, making immediate remediation essential for maintaining system security.