CVE-2014-3263 in IOS
Summary
by MITRE
The ScanSafe module in Cisco IOS 15.3(3)M allows remote attackers to cause a denial of service (device reload) via HTTPS packets that require tower processing, aka Bug ID CSCum97038.
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Analysis
by VulDB Data Team • 05/28/2017
The vulnerability described in CVE-2014-3263 represents a critical denial of service flaw within Cisco IOS software, specifically affecting the ScanSafe module in version 15.3(3)M. This issue manifests when the system processes HTTPS packets that necessitate tower processing, creating a condition where remote attackers can exploit the flaw to force device reloads and consequently disrupt network services. The vulnerability impacts Cisco IOS devices that utilize the ScanSafe security module, which is designed to provide web security filtering and protection against malicious content. The flaw specifically targets the processing logic within the network operating system that handles secure web traffic, making it particularly dangerous in enterprise environments where continuous network availability is essential.
The technical implementation of this vulnerability stems from improper handling of HTTPS traffic within the ScanSafe module's tower processing functionality. When the system receives specially crafted HTTPS packets, the processing routine fails to properly validate or handle the incoming data, leading to a condition that triggers an unexpected system reload. This behavior aligns with CWE-248, which addresses improper exception handling that can lead to unexpected program termination or system instability. The vulnerability exists because the code does not adequately validate the structure or content of HTTPS packets before attempting tower processing, creating a path where malformed or specially constructed traffic can cause the device to crash and restart. The flaw demonstrates a classic example of insufficient input validation in network security modules, where the system fails to properly sanitize external inputs before processing them.
The operational impact of CVE-2014-3263 extends beyond simple service disruption to potentially severe network reliability issues. When exploited, the vulnerability forces device reloads that can take several minutes to complete, during which time network services become unavailable to legitimate users. This disruption can cascade through network infrastructure, affecting multiple services and potentially creating security gaps while the device reboots. The attack vector is particularly concerning because it requires no authentication and can be executed remotely, making it accessible to any attacker with network connectivity to the affected device. This characteristic places the vulnerability within the ATT&CK framework's T1499 category, which encompasses network denial of service attacks that can be executed remotely without requiring user interaction or authentication. Organizations using affected Cisco IOS versions face significant risk of unauthorized service disruption, potentially leading to business continuity issues and increased operational overhead during recovery periods.
Mitigation strategies for this vulnerability should focus on immediate software updates and network segmentation approaches. Cisco has released patches addressing this specific flaw in subsequent IOS releases, making patch management a critical first step for affected organizations. The recommended solution involves upgrading to Cisco IOS version 15.3(3)M2 or later, which contains the necessary code modifications to properly handle HTTPS packets during tower processing. Network administrators should also implement monitoring solutions to detect unusual traffic patterns that might indicate exploitation attempts, particularly around HTTPS traffic processing. Additionally, implementing network access controls to limit direct access to devices running the vulnerable ScanSafe module can reduce the attack surface. Organizations should consider temporarily disabling the ScanSafe module if immediate patching is not feasible, though this approach reduces overall security coverage. The vulnerability also highlights the importance of comprehensive security testing for network security modules, particularly those handling encrypted traffic, as proper validation and error handling are essential for maintaining system stability under attack conditions.