CVE-2020-3211 in IOS XE
Summary
by MITRE
A vulnerability in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker to execute arbitrary commands with root privileges on the underlying operating system of an affected device. The vulnerability is due to improper input sanitization. An attacker who has valid administrative access to an affected device could exploit this vulnerability by supplying a crafted input parameter on a form in the web UI and then submitting that form. A successful exploit could allow the attacker to execute arbitrary commands with root privileges on the device, which could lead to complete system compromise.
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Analysis
by VulDB Data Team • 10/21/2020
This vulnerability resides within the web user interface of Cisco IOS XE Software, representing a critical security flaw that enables authenticated remote code execution with root privileges. The issue stems from inadequate input sanitization mechanisms that fail to properly validate and sanitize user-supplied data before processing. According to CWE-20, this vulnerability classifies as a weakness in input validation where insufficient sanitization allows malicious input to bypass security controls. The vulnerability specifically affects devices running Cisco IOS XE Software versions that are susceptible to command injection attacks through the web UI interface.
The technical exploitation occurs when an authenticated attacker with administrative privileges manipulates input parameters within web forms, leveraging the improper sanitization to inject malicious commands. This type of vulnerability aligns with ATT&CK technique T1059.001 for command and script injection, where adversaries execute code through compromised interfaces. The attack vector requires valid administrative credentials, making it a privilege escalation vulnerability rather than a lateral movement primitive. The flaw essentially allows an attacker who has already established administrative access to escalate their privileges to root level, thereby gaining complete control over the underlying operating system.
The operational impact of this vulnerability is severe as it provides attackers with full system compromise capabilities, enabling them to manipulate device configurations, extract sensitive data, install malware, or establish persistence mechanisms. The compromised device could serve as a foothold for further attacks within the network, potentially leading to widespread security breaches. Organizations relying on Cisco IOS XE Software for their network infrastructure face significant risk, as this vulnerability undermines the fundamental security assumptions of administrative access controls. The vulnerability affects multiple Cisco IOS XE Software versions, making it particularly concerning for enterprises with diverse network equipment deployments.
Mitigation strategies should prioritize immediate patching of affected devices with Cisco's security advisories, which typically address the root cause through proper input sanitization and validation mechanisms. Network segmentation and least privilege access controls can help limit the potential impact if exploitation occurs. Monitoring for suspicious administrative activities and implementing robust network access controls further reduces risk exposure. Security teams should also consider disabling unnecessary web UI interfaces when possible and implementing multi-factor authentication for administrative access to strengthen overall security posture against such vulnerabilities.