CVE-2015-0598 in IOS
Summary
by MITRE
The RADIUS implementation in Cisco IOS and IOS XE allows remote attackers to cause a denial of service (device reload) via crafted IPv6 Attributes in Access-Accept packets, aka Bug IDs CSCur84322 and CSCur27693.
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Analysis
by VulDB Data Team • 12/02/2024
The vulnerability identified as CVE-2015-0598 represents a critical denial of service flaw within Cisco IOS and IOS XE operating systems that specifically affects the RADIUS protocol implementation. This vulnerability manifests when the system processes Access-Accept packets containing malformed IPv6 attributes, leading to unexpected device behavior and ultimately resulting in complete system reloads. The flaw impacts network infrastructure devices that rely on RADIUS authentication for access control, potentially compromising network availability and operational continuity. Cisco has documented this issue under bug IDs CSCur84322 and CSCur27693, indicating the severity and scope of the problem within their product line.
The technical root cause of this vulnerability lies in the insufficient input validation within the RADIUS processing module of Cisco IOS and IOS XE systems. When a device receives an Access-Accept packet containing crafted IPv6 attributes, the system fails to properly sanitize or validate these attributes before processing them. This lack of proper validation creates a condition where malformed IPv6 data structures can trigger memory corruption or stack overflow scenarios within the RADIUS implementation. The vulnerability specifically exploits the handling of IPv6 attributes, which are typically used for extended network information exchange in RADIUS protocols, but the implementation fails to account for malformed or unexpected data formats that could cause the system to crash during processing.
From an operational perspective, this vulnerability presents significant risk to network infrastructure security and availability. Remote attackers can exploit this flaw without requiring authentication credentials, making it particularly dangerous as it can be leveraged by anyone with network access to the affected devices. The consequence of exploitation results in immediate device reload or reboot, effectively creating a denial of service condition that can disrupt network services for extended periods. This vulnerability impacts various Cisco devices including routers, switches, and wireless access points that utilize RADIUS authentication, potentially affecting large-scale network operations and enterprise environments where continuous availability is critical for business operations.
The vulnerability aligns with CWE-129, which addresses the weakness of insufficient input validation, and represents a classic example of how improper data handling can lead to system instability. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique for network denial of service, specifically targeting network infrastructure devices through protocol manipulation. Organizations should prioritize implementing mitigations including applying Cisco security patches, implementing network segmentation to limit exposure, and configuring access controls to restrict unauthorized access to RADIUS servers. Additionally, monitoring for unusual RADIUS traffic patterns and implementing intrusion detection systems can help identify potential exploitation attempts. The vulnerability underscores the importance of proper input validation and robust error handling in network protocol implementations, particularly in critical infrastructure components where reliability and availability are paramount for maintaining business continuity and network security.