CVE-2025-20315 in IOS XE
Summary
by MITRE • 09/24/2025
A vulnerability in the Network-Based Application Recognition (NBAR) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, causing a denial of service (DoS) condition.
This vulnerability is due to improper handling of malformed Control and Provisioning of Wireless Access Points (CAPWAP) packets. An attacker could exploit this vulnerability by sending malformed CAPWAP packets through an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.
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Analysis
by VulDB Data Team • 09/24/2025
The vulnerability identified as CVE-2025-20315 represents a critical denial of service weakness within Cisco IOS XE Software's Network-Based Application Recognition (NBAR) functionality. This flaw specifically targets the processing of Control and Provisioning of Wireless Access Points (CAPWAP) protocol packets, which are fundamental to wireless network infrastructure management. The NBAR feature is designed to identify and classify network traffic based on application protocols, making it a critical component in network monitoring and security policy enforcement. When an attacker exploits this vulnerability, they can trigger a device reload through the careful crafting of malformed CAPWAP packets that the system cannot properly handle, resulting in complete service disruption for network users.
The technical root cause of this vulnerability stems from inadequate input validation and error handling within the CAPWAP packet processing module of the NBAR feature. When the affected Cisco IOS XE devices receive malformed CAPWAP packets, the system fails to properly validate the packet structure and content before attempting to process them. This improper handling creates a condition where the device's memory management and packet processing routines become corrupted, leading to unexpected system behavior and ultimately causing the device to reboot. The vulnerability specifically affects the way the software handles malformed CAPWAP control messages that are used to establish and maintain communication between wireless access points and wireless controllers. This flaw aligns with CWE-129, which describes improper validation of input boundaries, and represents a classic example of insufficient input sanitization that can lead to system instability.
The operational impact of this vulnerability extends beyond simple service disruption, as it can affect critical network infrastructure components that support enterprise wireless communications. Network administrators may experience unexpected downtime, potentially affecting business operations, employee productivity, and customer service delivery. The remote and unauthenticated nature of the exploit means that attackers can initiate the DoS condition from outside the network perimeter, making it particularly dangerous for organizations with exposed network devices. The vulnerability affects multiple Cisco IOS XE software versions, particularly those that include the NBAR feature, and impacts various hardware platforms that support wireless networking functionality. This makes the attack surface broad and increases the potential for widespread disruption across different network environments.
Organizations should implement immediate mitigations to protect against this vulnerability, including applying the latest Cisco security patches and updates to affected devices. Network segmentation and access control measures can help limit the potential impact of such attacks by preventing unauthorized access to network infrastructure components. Monitoring network traffic for suspicious CAPWAP packet patterns and implementing intrusion detection systems can provide early warning of exploitation attempts. The vulnerability also highlights the importance of network resilience planning and incident response procedures, as organizations need to be prepared to handle unexpected device reboots and maintain backup communication pathways. Security teams should consider implementing rate limiting for CAPWAP traffic and establishing automated alerting mechanisms to detect abnormal device behavior that might indicate exploitation attempts. This vulnerability serves as a reminder of the critical importance of maintaining up-to-date network security measures and the potential consequences of insufficient input validation in network protocol processing.