CVE-2018-1156 in MikroTik
Summary
by MITRE
Mikrotik RouterOS before 6.42.7 and 6.40.9 is vulnerable to stack buffer overflow through the license upgrade interface. This vulnerability could theoretically allow a remote authenticated attacker execute arbitrary code on the system.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 03/17/2020
The vulnerability identified as CVE-2018-1156 affects Mikrotik RouterOS versions prior to 6.42.7 and 6.40.9, presenting a critical stack buffer overflow condition within the license upgrade interface. This flaw represents a significant security weakness that could be exploited by remote authenticated attackers to gain arbitrary code execution capabilities on affected systems. The vulnerability specifically manifests when the system processes license upgrade requests through its interface, creating an opportunity for malicious input to overflow stack memory buffers and potentially compromise the entire router operating system.
The technical implementation of this vulnerability stems from insufficient input validation and bounds checking within the license upgrade functionality. When legitimate users attempt to upgrade their router licenses through the web interface or API, the system fails to properly validate the size and content of incoming data structures. This allows an authenticated attacker to craft specially formatted license upgrade requests that exceed the allocated stack buffer space, causing a buffer overflow condition that can be leveraged to overwrite critical memory locations including return addresses and function pointers. The CWE-121 category applies directly to this vulnerability, as it represents a classic stack-based buffer overflow where insufficient bounds checking permits data to overwrite adjacent memory locations, potentially enabling code execution.
The operational impact of this vulnerability extends beyond simple remote code execution, as it fundamentally compromises the integrity and confidentiality of network infrastructure. Network administrators who rely on Mikrotik routers for critical network functions face significant risk of unauthorized access to their entire network infrastructure, potentially enabling attackers to modify routing tables, intercept traffic, or establish persistent backdoors. The authenticated nature of the exploit means that attackers must first obtain valid credentials, but this requirement does not significantly mitigate the risk since router administrative accounts are often well-known or easily obtained through other means. This vulnerability aligns with ATT&CK technique T1059.007 for command and script interpreter execution, as successful exploitation could enable attackers to execute arbitrary commands on the compromised device.
Mitigation strategies for CVE-2018-1156 require immediate patching of all affected RouterOS versions to the latest stable releases, specifically versions 6.42.7 and 6.40.9 or higher. Organizations should implement network segmentation to limit access to router management interfaces and enforce strict authentication controls including multi-factor authentication for administrative access. Network monitoring should be enhanced to detect unusual license upgrade activities or malformed requests that could indicate exploitation attempts. Additionally, regular security assessments of network infrastructure should include verification of firmware versions and patch compliance to prevent similar vulnerabilities from remaining unaddressed. The vulnerability demonstrates the critical importance of maintaining current firmware versions and implementing robust network access controls to prevent exploitation of authenticated remote code execution vulnerabilities in network infrastructure devices.