CVE-2018-15376 in IOS
Summary
by MITRE
A vulnerability in the embedded test subsystem of Cisco IOS Software for Cisco 800 Series Industrial Integrated Services Routers could allow an authenticated, local attacker to write arbitrary values to arbitrary locations in the memory space of an affected device. The vulnerability is due to the presence of certain test commands that were intended to be available only in internal development builds of the affected software. An attacker could exploit this vulnerability by using these commands on an affected device. A successful exploit could allow the attacker to write arbitrary values to arbitrary locations in the memory space of the affected device.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 03/30/2020
The vulnerability identified as CVE-2018-15376 represents a critical security flaw within the embedded test subsystem of Cisco IOS Software running on Cisco 800 Series Industrial Integrated Services Routers. This issue stems from the improper inclusion of internal development commands that should have been restricted to laboratory environments only. The flaw manifests as an insecure command execution mechanism that permits authenticated local users to manipulate memory addresses directly, bypassing normal security boundaries that protect the router's operational integrity. Such a vulnerability fundamentally undermines the device's security model by providing unauthorized memory manipulation capabilities to individuals with legitimate access credentials.
The technical exploitation of this vulnerability occurs through the use of specific test commands that were never intended for production environments but somehow made their way into released software versions. These commands operate outside the normal operational constraints of the router's software, allowing an authenticated attacker to specify arbitrary memory locations and write predetermined values to those locations. The flaw essentially creates a memory corruption pathway that could be leveraged to overwrite critical system components, modify operational parameters, or potentially establish persistent access points within the device's memory space. This type of vulnerability is classified under CWE-264 as "Permissions, Privileges, and Access Controls" and specifically relates to the improper restriction of operations within a memory address space.
The operational impact of CVE-2018-15376 extends beyond simple privilege escalation to encompass potential system compromise and operational disruption for industrial environments that rely on these routers. Industrial Integrated Services Routers serve as critical network infrastructure components in manufacturing, energy, and control systems where uninterrupted operation is paramount. An attacker who successfully exploits this vulnerability could potentially cause device instability, create backdoors for future access, or manipulate routing decisions that could affect entire industrial networks. The memory manipulation capability could be used to corrupt system firmware, alter configuration settings, or disable security features, making it particularly dangerous in environments where these devices control critical infrastructure operations. This vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation.
Cisco's response to this vulnerability required immediate patching of affected systems and implementation of access controls to limit who could execute the problematic commands. Organizations should ensure that only authorized personnel with legitimate development or testing requirements have access to these potentially dangerous test commands. The vulnerability highlights the importance of proper software release processes and the need for comprehensive security reviews of all code included in production builds. Network administrators should implement strict access controls, monitor for unauthorized command execution, and maintain up-to-date security patches to protect against similar vulnerabilities in embedded systems. Regular security assessments of industrial control systems should include verification that development-only features have been properly disabled in production environments. The incident underscores the critical need for maintaining clear separation between development and production environments, particularly in industrial settings where the stakes of security breaches can be catastrophic to operational continuity and safety.