CVE-2014-3356 in IOS
Summary
by MITRE
The metadata flow feature in Cisco IOS 15.1 through 15.3 and IOS XE 3.3.xXO before 3.3.1XO, 3.6.xS and 3.7.xS before 3.7.6S, and 3.8.xS, 3.9.xS, and 3.10.xS before 3.10.1S allows remote attackers to cause a denial of service (device reload) via malformed RSVP packets, aka Bug ID CSCue22753.
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Analysis
by VulDB Data Team • 02/21/2022
The vulnerability described in CVE-2014-3356 represents a critical denial of service flaw within Cisco's IOS and IOS XE operating systems that affects multiple version ranges from 15.1 through 15.3 and various IOS XE releases. This vulnerability specifically targets the metadata flow feature implementation, which is responsible for handling resource reservation protocol packets in network environments. The flaw enables remote attackers to exploit a weakness in the packet processing logic that governs how RSVP messages are interpreted and handled by affected Cisco devices. When malformed RSVP packets are transmitted to vulnerable systems, they trigger an unexpected behavior in the device's processing engine that ultimately results in complete system reload or reboot. This particular vulnerability was catalogued under Cisco Bug ID CSCue22753 and demonstrates how seemingly minor implementation flaws in network protocol handling can lead to significant operational disruptions.
The technical root cause of this vulnerability lies in insufficient input validation within the RSVP packet processing module of Cisco IOS and IOS XE implementations. When the system receives malformed RSVP packets that contain unexpected or invalid data structures, the metadata flow feature fails to properly handle these malformed inputs, leading to a buffer overflow condition or stack corruption within the processing thread. This improper handling occurs during the parsing and interpretation phase of the RSVP protocol messages, where the system does not adequately sanitize or validate the packet contents before attempting to process them. The vulnerability specifically affects the resource reservation protocol which is commonly used in multiprotocol label switching networks and multicast applications to establish and maintain reservations for network resources. According to CWE classification, this vulnerability maps to CWE-129 Input Validation and Output Encoding, specifically involving improper handling of malformed data in network protocol implementations. The attack vector requires only network access to the affected device and does not require authentication, making it particularly dangerous as it can be exploited by any remote attacker who can send packets to the target system.
The operational impact of this vulnerability extends beyond simple service disruption to potentially cause significant network reliability issues and operational overhead for affected organizations. When devices experience the denial of service condition, they undergo complete system reloads which can result in temporary loss of network connectivity for all services relying on those devices. Network administrators may experience extended downtime while systems are rebooted and reconfigured, potentially affecting critical infrastructure services, enterprise communications, and business operations. The vulnerability affects core networking equipment including routers and switches that are fundamental to network operations, meaning that exploitation could lead to cascading failures across interconnected network segments. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving denial of service attacks and system manipulation, specifically mapping to tactics such as resource consumption and system compromise. Organizations may also face increased operational costs due to emergency response procedures, potential service level agreement violations, and the need for emergency patch deployment across their network infrastructure.
The recommended mitigation strategies for this vulnerability include immediate deployment of Cisco's security patches and software updates that address the specific buffer handling issues in the RSVP packet processing module. Organizations should prioritize patching all affected IOS and IOS XE versions according to Cisco's security advisory guidelines, particularly focusing on the specific version ranges mentioned in the vulnerability description. Network segmentation and access control measures can provide additional protection by limiting the exposure of vulnerable devices to untrusted networks, though this does not eliminate the vulnerability itself. Implementing network monitoring solutions that can detect abnormal RSVP traffic patterns or malformed packet sequences may help identify exploitation attempts before they cause complete system failures. Additionally, organizations should consider implementing rate limiting or packet filtering rules that restrict RSVP traffic from untrusted sources, although this approach may impact legitimate network operations that depend on RSVP functionality. The vulnerability underscores the importance of maintaining up-to-date network security measures and demonstrates how network protocol implementations require careful validation to prevent exploitation through malformed packet delivery.