CVE-2013-5540 in Identity Services Engine Software
Summary
by MITRE
The file-upload feature in Cisco Identity Services Engine (ISE) allows remote authenticated users to cause a denial of service (disk consumption and administration-interface outage) by uploading many files, aka Bug ID CSCui67519.
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Analysis
by VulDB Data Team • 03/01/2019
The vulnerability described in CVE-2013-5540 affects Cisco Identity Services Engine (ISE) version 1.0 through 1.2, representing a significant denial of service weakness that can be exploited by authenticated attackers. This issue resides within the file upload functionality of the ISE platform, which is designed to manage network access control and identity verification services for enterprise environments. The vulnerability specifically targets the administrative interface of the system, making it particularly dangerous as it can disrupt critical network security operations. The bug ID CSCui67519 indicates this was a documented issue within Cisco's internal tracking systems, highlighting the organization's awareness of the problem before public disclosure. The affected version range suggests this was a persistent flaw that required multiple releases to address properly.
The technical flaw manifests through improper handling of file upload operations within the ISE administrative interface. When authenticated users upload multiple files through the vulnerable feature, the system fails to adequately manage disk space allocation and file storage processes. This leads to uncontrolled consumption of available disk resources, eventually causing the system to become unresponsive or crash entirely. The implementation lacks proper validation mechanisms to limit the number or size of files that can be uploaded simultaneously, nor does it enforce adequate resource management policies during the upload process. The vulnerability essentially allows for a resource exhaustion attack where the attacker can flood the system with files until it runs out of disk space, triggering the denial of service condition.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise network security operations and business continuity. When the administrative interface becomes unavailable due to disk exhaustion, network administrators lose access to critical configuration and monitoring capabilities within the ISE platform. This creates a cascading effect where network access control policies cannot be managed or updated, potentially allowing unauthorized access to network resources. The attack requires only authenticated access, meaning that someone with legitimate credentials could exploit this weakness, making it particularly concerning for environments where privileged accounts might be compromised. Organizations relying on ISE for network security would face significant operational challenges during such an attack, as they cannot manage or monitor their network access policies effectively.
Mitigation strategies for this vulnerability should focus on implementing proper access controls and resource management policies within the ISE platform. Organizations should ensure that all ISE systems are updated to versions that address this specific flaw, typically through Cisco's security advisory releases. Network administrators should implement monitoring solutions to track disk usage and file upload activities, enabling early detection of potential exploitation attempts. The implementation of upload size limits and file type restrictions can help prevent excessive resource consumption. Additionally, following the principle of least privilege and implementing multi-factor authentication for administrative access can reduce the risk of unauthorized exploitation. This vulnerability aligns with CWE-400, which addresses unchecked resource consumption, and represents a typical example of how insufficient input validation can lead to denial of service conditions in network security appliances. The attack vector demonstrates the importance of robust resource management in security platforms, as highlighted in various ATT&CK framework techniques related to privilege escalation and denial of service operations.