CVE-2020-3227 in IOS XE
Summary
by MITRE
A vulnerability in the authorization controls for the Cisco IOx application hosting infrastructure in Cisco IOS XE Software could allow an unauthenticated, remote attacker to execute Cisco IOx API commands without proper authorization. The vulnerability is due to incorrect handling of requests for authorization tokens. An attacker could exploit this vulnerability by using a crafted API call to request such a token. An exploit could allow the attacker to obtain an authorization token and execute any of the IOx API commands on an affected device.
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Analysis
by VulDB Data Team • 10/21/2020
The vulnerability identified as CVE-2020-3227 resides within the Cisco IOx application hosting infrastructure component of Cisco IOS XE Software, representing a critical authorization flaw that undermines the security posture of network devices. This vulnerability specifically targets the authorization token handling mechanism, creating a pathway for unauthenticated remote attackers to bypass legitimate authentication processes and gain unauthorized access to sensitive system functions. The IOx infrastructure serves as a platform for hosting third-party applications on Cisco network devices, making this vulnerability particularly concerning as it could enable attackers to execute arbitrary commands on affected systems. The flaw manifests in the improper validation and processing of authorization token requests, allowing malicious actors to craft specific API calls that circumvent normal authentication procedures and obtain valid tokens for system access.
The technical implementation of this vulnerability stems from inadequate input validation and authorization logic within the IOx API framework. When legitimate authorization token requests are processed, the system fails to properly verify the authenticity and legitimacy of the request parameters, creating a condition where crafted malicious requests can produce valid authorization tokens. This represents a classic authorization bypass vulnerability that aligns with CWE-285, which addresses improper authorization within software systems. The attacker's exploitation methodology involves sending specifically crafted API requests that exploit the flawed token generation or validation logic, ultimately resulting in the issuance of unauthorized tokens that grant full access to the IOx API functionality. The vulnerability's remote nature means that attackers do not require physical access or prior authentication credentials to exploit the flaw, making it particularly dangerous in network environments where such devices are exposed to external threats.
The operational impact of CVE-2020-3227 extends beyond simple unauthorized access, as the vulnerability enables complete control over the IOx application hosting infrastructure. Once an attacker obtains a valid authorization token, they can execute any IOx API command available on the affected device, potentially leading to complete system compromise, data exfiltration, or disruption of network services. This vulnerability directly maps to several ATT&CK techniques including T1078 for valid accounts and T1059 for command and script execution, as attackers can leverage the compromised authorization to run arbitrary commands and maintain persistent access. The potential for lateral movement within the network increases significantly, as compromised IOx infrastructure could serve as a foothold for further attacks against connected systems. Organizations may face severe consequences including regulatory violations, compliance breaches, and operational disruption, particularly in environments where IOx applications host critical network services or sensitive data processing capabilities.
Mitigation strategies for CVE-2020-3227 should prioritize immediate patch deployment from Cisco, as the vulnerability requires specific software updates to address the authorization token handling flaws. Network administrators should implement network segmentation to limit access to IOx-enabled devices and restrict API access through firewalls and access control lists. Monitoring and logging of API access attempts should be enhanced to detect anomalous token requests or unauthorized command executions. The implementation of principle of least privilege should be enforced, limiting the functionality available through the IOx API to only essential operations. Organizations should also consider disabling IOx functionality entirely if not required, as this provides the most effective defense against exploitation. Additionally, regular security assessments should be conducted to identify any unauthorized IOx applications or services running on network devices, and network access controls should be configured to prevent unauthorized external access to devices running vulnerable IOS XE software versions.