CVE-2018-1159 in MikroTik
Summary
by MITRE
Mikrotik RouterOS before 6.42.7 and 6.40.9 is vulnerable to a memory corruption vulnerability. An authenticated remote attacker can crash the HTTP server by rapidly authenticating and disconnecting.
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Analysis
by VulDB Data Team • 03/17/2020
The vulnerability identified as CVE-2018-1159 affects Mikrotik RouterOS versions prior to 6.42.7 and 6.40.9, representing a critical memory corruption flaw that can be exploited by authenticated remote attackers. This vulnerability specifically targets the HTTP server component of the router operating system, creating a pathway for denial-of-service attacks that can disrupt network services and potentially compromise system stability. The flaw manifests when an attacker rapidly authenticates to the HTTP server and subsequently disconnects, triggering a memory corruption state that ultimately leads to server crash. This type of vulnerability falls under the category of memory corruption issues that can result in system instability and service disruption, making it particularly dangerous in network infrastructure environments where router availability is paramount. The vulnerability is classified as CWE-121, which encompasses stack-based buffer overflow conditions, though this specific implementation involves memory corruption through authentication session management rather than traditional buffer overflows.
The technical exploitation of this vulnerability requires an attacker to possess valid authentication credentials, which limits its scope but does not eliminate the risk entirely. The rapid authentication and disconnection pattern creates a race condition within the HTTP server's session handling mechanism, where memory allocated for authentication contexts is not properly managed during the disconnection sequence. This improper memory management leads to corruption of heap or stack memory regions, causing the HTTP server process to terminate unexpectedly. The attack vector is classified as remote and authenticated, meaning that an attacker must first establish valid credentials to the router's HTTP interface, which could be obtained through various means including credential theft, default credential exploitation, or social engineering attacks. The vulnerability demonstrates the importance of proper session management and memory cleanup procedures in server applications, particularly those handling network authentication services.
The operational impact of CVE-2018-1159 extends beyond simple service disruption, as it can affect network availability and potentially provide attackers with opportunities to escalate privileges or conduct further reconnaissance. When the HTTP server crashes, it can interrupt legitimate network management operations and create windows of opportunity for more sophisticated attacks. Network administrators may experience unexpected service outages that can affect critical infrastructure operations, particularly in environments where router management interfaces are heavily relied upon for network monitoring and control. The vulnerability's exploitation pattern suggests that it could be used in conjunction with other attack vectors to create more complex attack scenarios, potentially allowing attackers to maintain persistence or escalate their privileges within the network infrastructure. This type of vulnerability can also serve as a reconnaissance tool, as attackers might use the crash conditions to identify potential targets or gather information about system configurations. The impact is particularly concerning in enterprise environments where router availability directly affects network performance and business continuity.
Mitigation strategies for CVE-2018-1159 should prioritize immediate patching of affected RouterOS versions to 6.42.7 or 6.40.9, which contain the necessary fixes for the memory corruption issue. Network administrators should also implement network segmentation and access controls to limit the attack surface, ensuring that only authorized personnel can access router management interfaces. Monitoring systems should be configured to detect unusual authentication patterns or repeated connection attempts that could indicate exploitation attempts. The implementation of secure authentication practices including multi-factor authentication and strong credential policies can significantly reduce the risk of unauthorized access to router management interfaces. Additionally, network administrators should consider implementing intrusion detection systems that can identify and alert on anomalous behavior patterns consistent with the vulnerability exploitation. From an operational security perspective, regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues before they can be exploited. The vulnerability underscores the importance of maintaining current security patches and implementing robust network access controls as part of comprehensive cybersecurity programs that align with industry standards such as those recommended by the NIST Cybersecurity Framework and ISO 27001 security management guidelines.