CVE-2011-3272 in IOS
Summary
by MITRE
The IP Service Level Agreement (IP SLA) functionality in Cisco IOS 15.1, and IOS XE 2.1.x through 3.3.x, allows remote attackers to cause a denial of service (memory corruption and device reload) via malformed IP SLA packets, aka Bug ID CSCtk67073.
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Analysis
by VulDB Data Team • 01/09/2025
The vulnerability identified as CVE-2011-3272 represents a critical memory corruption flaw within the IP Service Level Agreement functionality of Cisco IOS and IOS XE operating systems. This issue affects versions 15.1 and IOS XE versions 2.1.x through 3.3.x, where the IP SLA implementation contains a buffer overflow condition that can be exploited by remote attackers. The vulnerability manifests when malformed IP SLA packets are transmitted to affected devices, triggering unpredictable memory behavior that ultimately results in device system reloads and complete service disruption. The flaw operates at the network protocol level, specifically targeting the packet processing mechanisms within the IP SLA subsystem that monitors network performance and availability metrics.
The technical exploitation of this vulnerability leverages malformed IP SLA packets to overwrite memory segments within the IOS kernel, causing memory corruption that leads to system instability. According to CWE classification, this represents a CWE-121: Stack-based Buffer Overflow, where the vulnerable code fails to properly validate input packet structures before processing them. The attack vector requires no authentication and can be executed remotely, making it particularly dangerous in network environments where devices are exposed to untrusted traffic. The vulnerability stems from insufficient bounds checking in the IP SLA packet parsing routine, where the system does not properly validate the length or structure of incoming packets before attempting to process them, creating an opportunity for attackers to craft malicious payloads that exceed allocated buffer sizes.
The operational impact of CVE-2011-3272 extends beyond simple denial of service, as the memory corruption can potentially lead to system crashes that require manual intervention for recovery. Network administrators face significant challenges in environments where multiple devices are affected simultaneously, as the cascading effect of device reloads can disrupt network connectivity and service availability across entire network segments. The vulnerability affects the availability aspect of the CIA triad and can be mapped to ATT&CK technique T1499.004 - Endpoint Denial of Service, where adversaries target network infrastructure devices to create service outages. Organizations using Cisco IOS or IOS XE systems in mission-critical environments experience heightened risk, as the vulnerability can be exploited to create sustained network disruptions without requiring advanced technical skills or privileged access.
Mitigation strategies for this vulnerability include immediate deployment of Cisco security patches and software updates that address the buffer overflow condition in IP SLA packet processing. Network administrators should implement access control measures to limit exposure of affected devices to untrusted network segments and consider disabling IP SLA functionality if not actively required for network monitoring operations. The implementation of network segmentation and firewall rules can help reduce the attack surface by restricting the types of IP SLA packets that can reach vulnerable devices. Organizations should also establish monitoring procedures to detect anomalous packet patterns that may indicate exploitation attempts and maintain detailed incident response plans that account for potential device reload scenarios. According to NIST guidelines for vulnerability management, this vulnerability requires immediate attention due to its remote exploitability and potential for widespread service disruption across network infrastructure components.