CVE-2011-3270 in IOS
Summary
by MITRE
Unspecified vulnerability in Cisco IOS 12.2SB before 12.2(33)SB10 and 15.0S before 15.0(1)S3a on Cisco 10000 series routers allows remote attackers to cause a denial of service (device reload) via a sequence of crafted ICMP packets, aka Bug ID CSCtk62453.
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Analysis
by VulDB Data Team • 01/10/2025
The vulnerability identified as CVE-2011-3270 represents a significant denial of service weakness affecting Cisco IOS software versions within the 12.2SB and 15.0S release lines. This flaw specifically impacts Cisco 10000 series routers, which are widely deployed in enterprise and service provider networks for routing and switching functions. The vulnerability manifests through a carefully crafted sequence of Internet Control Message Protocol packets that can trigger an unexpected device reload, effectively disrupting network connectivity and service availability. The bug was catalogued under Cisco bug ID CSCtk62453, indicating its classification within the company's internal vulnerability tracking system.
The technical nature of this vulnerability stems from inadequate input validation within the ICMP processing subsystem of the affected IOS versions. When the router receives a sequence of specially formatted ICMP packets, the processing logic fails to properly handle the malformed data structures, leading to a memory corruption condition that ultimately causes the device to crash and automatically reload. This behavior represents a classic buffer overflow or input validation flaw that allows attackers to manipulate the normal operation of the routing device through network-based attacks. The vulnerability operates at the network protocol level, making it particularly dangerous as it can be exploited from remote locations without requiring physical access or authentication credentials.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise network stability and availability for extended periods. When a Cisco 10000 series router experiences a reload due to this vulnerability, it can result in temporary loss of network connectivity for all traffic passing through that device, potentially affecting multiple network segments or even entire network domains depending on the router's role in the network topology. The remote exploitation capability means that attackers can trigger this denial of service condition from anywhere on the internet, making it particularly attractive for malicious actors seeking to disrupt network services. Network administrators may experience significant downtime while the device recovers and re-establishes network connections, with potential cascading effects throughout the network infrastructure.
Mitigation strategies for this vulnerability should focus on immediate patch deployment to upgrade affected Cisco IOS versions to the patched releases mentioned in the advisory. Organizations should prioritize updating all affected Cisco 10000 series routers to versions 12.2(33)SB10 or later, and 15.0(1)S3a or later, which contain the necessary fixes to prevent the exploitation of this vulnerability. Network segmentation and access control measures can provide temporary protection by limiting the exposure of affected devices to untrusted networks. Additionally, implementing monitoring solutions that can detect unusual ICMP traffic patterns may help identify potential exploitation attempts before they succeed in causing device reloads. The vulnerability aligns with CWE-129, which covers improper validation of input boundaries, and represents a vector that could be categorized under ATT&CK technique T1499 for network disruption attacks. Organizations should also consider implementing network intrusion detection systems that can identify and alert on suspicious ICMP packet sequences that match the known exploitation patterns for this specific vulnerability.