CVE-2020-20262 in MikroTik
Summary
by MITRE • 07/21/2021
Mikrotik RouterOs before 6.47 (stable tree) suffers from an assertion failure vulnerability in the /ram/pckg/security/nova/bin/ipsec process. An authenticated remote attacker can cause a Denial of Service due to an assertion failure via a crafted packet.
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Analysis
by VulDB Data Team • 07/26/2021
The vulnerability identified as CVE-2020-20262 affects MikroTik RouterOS versions prior to 6.47, specifically within the ipsec process located at /ram/pckg/security/nova/bin/ipsec. This represents a critical assertion failure condition that can be exploited by authenticated remote attackers to induce a denial of service scenario. The flaw exists in the network security component responsible for IPsec protocol handling, which is fundamental to secure network communications and remote access solutions. The vulnerability demonstrates a classic software reliability issue where improper input validation leads to unexpected process termination.
The technical implementation of this vulnerability stems from inadequate validation of incoming packets within the IPsec processing pipeline. When an authenticated attacker sends a crafted packet to the affected RouterOS system, the assertion failure occurs in the ipsec binary process, causing the service to crash and restart. This assertion failure mechanism is typically implemented to catch programming errors during development but becomes exploitable when attackers can trigger these conditions in production environments. The vulnerability specifically targets the security package nova which handles IPsec implementations, making it particularly dangerous for organizations relying on MikroTik devices for secure network connectivity.
From an operational impact perspective, this vulnerability creates significant risk for network availability and security infrastructure. Organizations using affected MikroTik devices may experience unexpected service disruptions when attackers exploit this weakness, potentially leading to extended downtime for critical network services. The authenticated nature of the attack means that attackers must first gain access credentials, but once obtained, they can cause sustained denial of service conditions that could impact business continuity and network access for legitimate users. Network security teams face the additional challenge of monitoring for this specific attack pattern while maintaining service availability.
The vulnerability aligns with CWE-248, an unspecified weakness in the assertion failure category, and represents a direct violation of the principle of least privilege and robust error handling in network security applications. From an attack framework perspective, this vulnerability maps to the denial of service tactic within the MITRE ATT&CK framework, specifically targeting network infrastructure components. Organizations should implement immediate mitigation strategies including applying the official RouterOS patch version 6.47 or later, which resolves the assertion failure by implementing proper input validation and error handling mechanisms. Network segmentation and access controls should be strengthened to limit potential attacker access to the affected systems, while monitoring should be enhanced to detect unusual packet patterns that may indicate exploitation attempts.