CVE-2018-0623 in Kaikei
Summary
by MITRE
Untrusted search path vulnerability in Multiple Yayoi 17 Series products (Yayoi Kaikei 17 Series Ver.23.1.1 and earlier, Yayoi Aoiro Shinkoku 17 Ver.23.1.1 and earlier, Yayoi Kyuuyo 17 Ver.20.1.4 and earlier, Yayoi Kyuuyo Keisan 17 Ver.20.1.4 and earlier, Yayoi Hanbai 17 Series Ver. 20.0.2 and earlier, and Yayoi Kokyaku Kanri 17 Ver.11.0.2 and earlier) allows an attacker to gain privileges via a Trojan horse DLL in an unspecified directory. This flaw exists within the handling of msjet49.dll loaded by the vulnerable products.
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Analysis
by VulDB Data Team • 03/21/2020
The vulnerability described in CVE-2018-0623 represents a critical untrusted search path issue affecting multiple products in the Yayoi Kaikei 17 Series and related applications. This flaw manifests in the improper handling of dynamic link library (DLL) loading mechanisms, specifically involving the msjet49.dll component that is loaded by these vulnerable software products. The vulnerability stems from the software's failure to properly validate or restrict the directories from which DLL files are loaded, creating an exploitable condition that allows malicious actors to execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability follows the pattern of DLL injection attacks where an attacker places a malicious Trojan horse DLL in a directory that is searched before the legitimate system directories. When the vulnerable application attempts to load msjet49.dll, it inadvertently loads the attacker-controlled DLL instead of the legitimate one, thereby executing malicious code within the context of the target application. This behavior directly aligns with CWE-426 Untrusted Search Path, which describes how applications that search directories without proper validation can be tricked into loading malicious code.
The operational impact of this vulnerability is significant as it enables privilege escalation attacks that can compromise the integrity and confidentiality of sensitive financial and business data processed by these applications. Given that these products are designed for accounting, inventory management, and business operations, successful exploitation could lead to unauthorized access to financial records, transaction data, and customer information. The vulnerability affects multiple versions of Yayoi software products, indicating a widespread issue that would require coordinated patching across various business-critical applications.
Security professionals should note that this vulnerability maps to several ATT&CK techniques including T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation, as it enables attackers to execute code with elevated privileges. The attack vector leverages the trust relationship between the application and its DLL dependencies, making detection challenging as the malicious activity appears to originate from legitimate system components. Organizations should implement immediate mitigations including updating to patched versions of the affected software, implementing application whitelisting policies, and conducting security assessments to identify any compromised systems within their network infrastructure.
The root cause of this vulnerability demonstrates poor software development practices regarding DLL loading security and highlights the importance of implementing secure coding practices that prevent untrusted search paths. This issue serves as a reminder of the critical need for proper input validation, secure library loading mechanisms, and regular security updates to protect against exploitation of such fundamental flaws in enterprise software applications.