CVE-2012-4622 in Catalyst 4500E
Summary
by MITRE
Cisco IOS XE 03.02.00.XO.15.0(2)XO on Catalyst 4500E series switches, when a Supervisor Engine 7L-E card is installed, allows remote attackers to cause a denial of service (card reload) via malformed packets that trigger uncorrected ECC error messages, aka Bug ID CSCty88456.
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Analysis
by VulDB Data Team • 04/14/2021
The vulnerability identified as CVE-2012-4622 affects Cisco IOS XE software version 03.02.00.XO.15.0(2)XO running on Catalyst 4500E series switches equipped with Supervisor Engine 7L-E cards. This represents a critical denial of service flaw that can be exploited remotely by malicious actors to disrupt network operations. The vulnerability specifically manifests when the switch receives malformed packets that trigger uncorrected error correction code errors within the hardware processing components. The underlying issue lies in the insufficient handling of error conditions during packet processing, particularly when dealing with memory errors that are not properly managed by the system's error correction mechanisms.
The technical flaw stems from the failure of the Supervisor Engine 7L-E card to properly handle uncorrected error correction code errors that occur during packet processing operations. When malformed packets are received, they trigger memory errors that the system's error correction mechanisms cannot resolve, leading to a cascade of failures that ultimately results in the supervisor engine card being automatically reloaded. This reload process effectively brings the switch functionality to a halt, creating a denial of service condition that can persist until manual intervention occurs or the system automatically recovers. The vulnerability operates at the hardware-software interface level where packet processing and memory management intersect, making it particularly challenging to mitigate without addressing the root cause in the error handling logic.
The operational impact of this vulnerability extends beyond simple service disruption as it can affect network availability and reliability for extended periods. Network administrators may experience unexpected downtime of critical network infrastructure, particularly in environments where these switches serve as core routing or switching points. The automatic card reload process can occur without proper logging or alerting mechanisms, making it difficult for administrators to detect and respond to attacks promptly. Additionally, the vulnerability affects the entire Catalyst 4500E series with Supervisor Engine 7L-E cards, representing a significant risk to organizations that have deployed these specific hardware configurations. The remote nature of the attack means that adversaries can exploit this vulnerability from outside the network perimeter, potentially causing widespread disruption without requiring physical access or elevated privileges within the network.
This vulnerability aligns with CWE-129, which addresses issues related to insufficient input validation and error handling in memory management systems. The flaw demonstrates how inadequate error correction mechanisms can lead to system instability and denial of service conditions, particularly in enterprise networking equipment where reliability is paramount. From an attack perspective, this vulnerability maps to the ATT&CK technique T1499.004, which covers network denial of service attacks through system resource exhaustion or critical component failure. The exploitability of this vulnerability is enhanced by the fact that it requires no authentication or privilege escalation, making it particularly dangerous for network infrastructure that is exposed to untrusted traffic. Organizations should consider implementing network segmentation, access control lists, and monitoring solutions to detect and prevent exploitation attempts, while also prioritizing the deployment of Cisco's official security patches and updates to address the root cause of the error handling deficiency in the affected IOS XE software versions.