CVE-2014-3355 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 CSCug75942.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 02/21/2022
The vulnerability described in CVE-2014-3355 represents a critical denial of service flaw within Cisco's IOS and IOS XE operating systems that affects a significant portion of network infrastructure deployments. This issue specifically targets the metadata flow feature implementation, which is responsible for processing resource reservation protocol packets that are essential for quality of service operations in multicast and unicast network environments. The vulnerability manifests when devices process malformed RSVP packets that contain invalid or unexpected data structures, leading to improper state handling within the routing and forwarding modules. This flaw exists across multiple IOS versions including 15.1 through 15.3 and various IOS XE releases, indicating a widespread impact that would affect numerous enterprise and service provider networks relying on Cisco networking equipment for their core infrastructure.
The technical exploitation of this vulnerability occurs through the manipulation of RSVP packet formats that are typically used for bandwidth reservation and traffic engineering in multiprotocol label switching networks. When a specially crafted malformed RSVP packet reaches a vulnerable device, the metadata flow processing engine fails to properly validate the packet structure, causing memory corruption or state inconsistency that ultimately results in the device performing an unexpected reload operation. This process involves the device's internal packet processing modules encountering data that violates expected protocol formats, leading to stack corruption or memory management errors that trigger the system to restart as a protective measure. The vulnerability is particularly concerning because RSVP is commonly used in enterprise networks for voice and video services, making this denial of service attack capable of disrupting critical business communications.
From an operational impact perspective, this vulnerability presents a severe threat to network availability and business continuity, as unauthorized remote attackers can cause network devices to repeatedly reload without requiring any authentication credentials or privileged access. The attack can be executed from any location on the network where the attacker has access to send RSVP packets, making it particularly dangerous in environments where network segmentation is insufficient or where devices are exposed to untrusted network segments. Network administrators may experience frequent service disruptions, particularly during peak usage times when network resources are already constrained, and the automatic reload process can result in temporary loss of network connectivity for the affected device. The vulnerability also creates operational overhead as network teams must monitor for signs of exploitation, implement temporary workarounds, and plan for device reloads that can disrupt network services.
The mitigation strategies for this vulnerability require immediate attention from network administrators and should include implementing access control lists to filter RSVP traffic at network boundaries, applying Cisco's recommended software patches and upgrades to affected IOS and IOS XE versions, and configuring device monitoring to detect unusual reload patterns that may indicate exploitation attempts. Network segmentation should be enhanced to isolate critical network components from untrusted traffic sources, and network administrators should consider implementing rate limiting for RSVP packets to prevent abuse. This vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and may map to ATT&CK technique T1499.004 for network denial of service attacks. Organizations should also implement network intrusion detection systems to monitor for malformed RSVP traffic patterns and establish incident response procedures to quickly address exploitation attempts, as the vulnerability's impact can cascade through network infrastructure causing widespread service disruption across connected systems.