CVE-2013-3445 in Identity Services Engine
Summary
by MITRE
The firewall subsystem in Cisco Identity Services Engine has an incorrect rule for open ports, which allows remote attackers to cause a denial of service (CPU consumption or process crash) via a flood of malformed IP packets, aka Bug ID CSCug94572.
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Analysis
by VulDB Data Team • 01/04/2022
The vulnerability identified as CVE-2013-3445 resides within the firewall subsystem of Cisco Identity Services Engine platforms, representing a critical security flaw that undermines the system's ability to properly handle network traffic. This issue manifests through an incorrect rule implementation for open ports that fails to adequately validate incoming IP packet structures. The vulnerability specifically affects Cisco Identity Services Engine software versions where the firewall component does not correctly process malformed IP packets, creating an exploitable condition that remote attackers can leverage to disrupt normal system operations.
The technical flaw stems from insufficient input validation within the firewall subsystem's packet processing logic. When the system receives malformed IP packets, the incorrect rule implementation fails to properly sanitize or reject these packets before they reach the core processing components. This allows attackers to craft specific packet sequences that exploit the flawed validation mechanism, causing the system to consume excessive CPU resources or trigger process crashes. The vulnerability operates at the network protocol level, specifically targeting the IP packet handling capabilities of the firewall subsystem, making it particularly dangerous as it can affect the entire network access control functionality provided by the Identity Services Engine.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire network security infrastructure managed by the affected Cisco Identity Services Engine. Remote attackers can leverage this flaw to perform denial of service attacks that consume significant system resources, leading to complete service unavailability, or cause process crashes that require manual intervention and system restarts. The CPU consumption aspect of the attack can gradually degrade system performance until the device becomes unusable, while the process crash component can result in immediate service interruption that affects network access control policies. This vulnerability directly impacts the availability and reliability of network access services, potentially leaving networks exposed to unauthorized access during the period of system instability.
Organizations affected by CVE-2013-3445 should implement immediate mitigations including applying the relevant Cisco security patches and updates, implementing network segmentation to limit exposure, and configuring additional firewall rules to filter malformed IP traffic. The vulnerability aligns with CWE-129, which describes improper validation of input ranges, and represents a classic example of how inadequate input validation can lead to resource exhaustion attacks. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique for network denial of service, where adversaries leverage system weaknesses to disrupt network services. Additionally, the issue demonstrates characteristics of T1566.001 for initial access through network services, as attackers may use this vulnerability to establish a foothold before escalating their attacks. The attack surface is particularly concerning for organizations relying on Cisco Identity Services Engine for network access control, as successful exploitation can effectively disable critical network security functions and potentially provide attackers with opportunities to bypass access controls and gain unauthorized network access.