CVE-2018-6765 in MySwisscomAssistant
Summary
by MITRE
Swisscom MySwisscomAssistant 2.17.1.1065 contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code on the targeted system. This vulnerability exists due to the way .dll files are loaded. It allows an attacker to load a .dll of the attacker's choosing that could execute arbitrary code without the user's knowledge. The specific flaw exists within the handling of several DLLs (dwmapi.dll, IPHLPAPI.DLL, WindowsCodecs.dll, RpcRtRemote.dll, CRYPTSP.dll, rasadhlp.dll, DNSAPI.dll, ntmarta.dll, netbios.dll, olepro32.dll, security.dll, winhttp.dll, WINSTA.dll) loaded by the MySwisscomAssistant_Setup.exe process.
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Analysis
by VulDB Data Team • 01/17/2020
The vulnerability identified as CVE-2018-6765 affects Swisscom MySwisscomAssistant version 2.17.1.1065, presenting a critical security flaw that enables unauthenticated remote code execution. This represents a significant threat vector where attackers can compromise systems without requiring user interaction or authentication credentials. The vulnerability stems from improper dynamic link library loading mechanisms within the application's installation process, specifically within the MySwisscomAssistant_Setup.exe executable. The flaw manifests through the application's handling of multiple system DLLs including dwmapi.dll, IPHLPAPI.DLL, WindowsCodecs.dll, and several others that are loaded during the setup process.
The technical implementation of this vulnerability follows a classic DLL injection attack pattern that aligns with CWE-426 Untrusted Pointer Dereference and CWE-122 Heap-based Buffer Overflow. Attackers can manipulate the DLL loading sequence by placing malicious DLL files in directories that are searched before the legitimate system directories, exploiting the predictable search order behavior of Windows application loading mechanisms. This vulnerability operates under the principle of DLL hijacking where the application loads attacker-controlled code instead of the intended system libraries, effectively providing a backdoor for arbitrary code execution. The attack requires no user interaction since the malicious DLL loading occurs automatically during the installation process.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise and potential lateral movement within network environments. An attacker who successfully exploits this vulnerability can gain full control over the targeted system, potentially leading to data exfiltration, privilege escalation, or use of the compromised system as a pivot point for attacking other networked devices. This vulnerability particularly affects enterprise environments where the Swisscom MySwisscomAssistant application may be deployed across multiple systems, creating a potential attack surface that could be leveraged for widespread compromise. The remote nature of the attack means that exploitation can occur from any location without requiring physical access to the target system.
Mitigation strategies for CVE-2018-6765 should focus on immediate patching of the affected software version, with administrators implementing strict application whitelisting policies to prevent unauthorized DLL loading. The recommended approach includes disabling the ability of applications to load DLLs from arbitrary locations and enforcing secure DLL loading practices through Windows security features such as Windows Defender Application Control or AppLocker. Additionally, network segmentation and monitoring should be implemented to detect anomalous DLL loading behavior, with security teams leveraging ATT&CK framework techniques such as T1059 Command and Scripting Interpreter and T1073 DLL Side-Loading to identify and respond to exploitation attempts. Organizations should also consider implementing runtime application protection measures and regular security assessments to identify similar vulnerabilities in other applications within their environment.