CVE-2008-2060 in Intrusion Prevention System
Summary
by MITRE
Unspecified vulnerability in Cisco Intrusion Prevention System (IPS) 5.x before 5.1(8)E2 and 6.x before 6.0(5)E2, when inline mode and jumbo Ethernet support are enabled, allows remote attackers to cause a denial of service (panic), and possibly bypass intended restrictions on network traffic, via a "specific series of jumbo Ethernet frames."
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Analysis
by VulDB Data Team • 08/11/2019
The vulnerability identified as CVE-2008-2060 represents a critical flaw in Cisco's Intrusion Prevention System software that affects versions 5.x prior to 5.1(8)E2 and 6.x prior to 6.0(5)E2. This weakness specifically manifests when the IPS device operates in inline mode with jumbo Ethernet frame support enabled, creating a dangerous condition that can be exploited by remote attackers to compromise system stability and potentially circumvent network security controls. The vulnerability falls under the category of unspecified weakness, indicating that the exact technical root cause was not fully detailed in the initial disclosure, though subsequent analysis has identified the issue as related to improper handling of large Ethernet frames within the IPS processing pipeline.
When jumbo Ethernet frames are processed in inline mode, the IPS system's packet processing mechanisms encounter a condition that causes the device to panic and crash, resulting in a complete denial of service for the protected network segment. This panic condition occurs due to the system's inability to properly manage the extended frame sizes that exceed standard Ethernet MTU limits, leading to memory corruption or buffer overflow conditions within the IPS engine. The vulnerability is particularly concerning because it affects inline deployment scenarios where the IPS device serves as a direct network bridge, making it a prime target for attackers seeking to disrupt network operations or establish persistent access points.
The operational impact of this vulnerability extends beyond simple service disruption to include potential security bypass capabilities that could allow attackers to evade network monitoring and control mechanisms. When the IPS device panics and crashes, it may inadvertently allow malicious traffic to pass through without proper inspection, effectively creating a window of opportunity for attackers to exploit other vulnerabilities or establish unauthorized access to the network. This dual nature of the vulnerability - causing both denial of service and potential bypass of security controls - makes it particularly dangerous in enterprise environments where network availability and security are paramount. The attack vector requires only remote access to send specifically crafted jumbo frames, making exploitation relatively simple and accessible to threat actors with basic network knowledge.
Cisco addressed this vulnerability through software updates that included enhanced frame processing logic and improved buffer management when handling jumbo Ethernet frames in inline mode. The fix involved implementing proper bounds checking and memory allocation strategies to prevent the panic conditions that occurred during frame processing. Organizations should implement the recommended software patches immediately to mitigate this risk, as the vulnerability affects critical network infrastructure components. Network administrators should also consider implementing additional monitoring to detect unusual traffic patterns that might indicate exploitation attempts. This vulnerability aligns with CWE-129, which covers improper validation of length fields, and maps to ATT&CK technique T1499.004 for network denial of service attacks. The incident highlights the importance of proper input validation and buffer management in network security appliances, particularly when handling variable-length data structures such as jumbo frames that exceed standard network parameters. Organizations should conduct comprehensive vulnerability assessments to identify all affected devices and ensure that inline IPS deployments are properly configured to avoid exposing systems to this class of attack.