CVE-2008-0352 in Linux
Summary
by MITRE
The Linux kernel 2.6.20 through 2.6.21.1 allows remote attackers to cause a denial of service (panic) via a certain IPv6 packet, possibly involving the Jumbo Payload hop-by-hop option (jumbogram).
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 10/14/2024
The vulnerability described in CVE-2008-0352 represents a critical denial of service flaw affecting Linux kernel versions 2.6.20 through 2.6.21.1. This issue specifically targets the IPv6 implementation within the kernel's networking stack, creating a condition where remote attackers can trigger system panics through carefully crafted IPv6 packets. The vulnerability stems from insufficient validation of the Jumbo Payload hop-by-hop option, which is a legitimate IPv6 extension that allows packets larger than the standard 65535 byte limit to be transmitted across networks. When the kernel processes these malformed jumbograms, it fails to properly handle the oversized packet structure, leading to a kernel panic that results in complete system unavailability.
The technical root cause of this vulnerability lies in the kernel's handling of IPv6 extension headers, particularly the Jumbo Payload option that is designed to support packets exceeding the standard maximum transmission unit. The flaw occurs during the processing of hop-by-hop options where the kernel does not adequately validate the length field of the jumbo payload option. This validation failure creates a condition where an attacker can construct an IPv6 packet with a malformed jumbo payload option that causes integer overflow or buffer overflows within kernel memory structures. The vulnerability is classified under CWE-129 Input Validation and CWE-787 Out-of-bounds Write, both of which are fundamental weaknesses in input sanitization and memory management that have been consistently exploited in kernel-level attacks.
From an operational perspective, this vulnerability presents a significant risk to network infrastructure and systems running affected Linux kernel versions. The remote nature of the attack means that any system processing IPv6 traffic could be compromised without requiring local access or authentication. The impact manifests as immediate system panics that result in complete service disruption, forcing administrators to restart affected systems and potentially causing cascading failures in networked environments. Network administrators should note that the vulnerability affects systems that have IPv6 enabled, which is increasingly common in modern deployments, making the attack surface broader than initially apparent. The attack can be executed from any network location with access to the vulnerable system, making it particularly dangerous for publicly accessible servers and network infrastructure components.
The attack pattern associated with CVE-2008-0352 follows the ATT&CK framework's T1499.004 technique for Network Denial of Service, where adversaries leverage protocol implementation flaws to cause system crashes. This vulnerability can be exploited by sending specially crafted IPv6 packets containing malformed jumbo payload options to any system with IPv6 enabled and listening for incoming traffic. The exploit requires minimal privileges and can be automated, making it particularly dangerous for large-scale attacks. Organizations should consider implementing network segmentation and firewall rules to block IPv6 traffic where not required, though this approach may not be feasible in IPv6-enabled environments. The vulnerability also aligns with ATT&CK technique T1595.001 for Network Device Firmware, as it affects the kernel's network processing capabilities rather than higher-level applications.
Mitigation strategies for this vulnerability primarily focus on immediate kernel updates to versions 2.6.21.2 or later, which contain the necessary patches to properly validate jumbo payload options in IPv6 packets. System administrators should prioritize patching affected systems, particularly those handling IPv6 traffic or serving as network infrastructure components. Additional defensive measures include implementing IPv6 traffic filtering rules at network boundaries to drop packets with malformed hop-by-hop options, though this approach may impact legitimate traffic. Organizations should also consider disabling IPv6 on systems where it is not required, as this eliminates the attack surface entirely. The vulnerability demonstrates the importance of proper input validation in kernel space, where even minor flaws can result in complete system compromise. Security monitoring should include detection of unusual network traffic patterns and system restarts that might indicate exploitation attempts. Regular vulnerability assessments and kernel updates remain critical for maintaining system security posture against similar protocol implementation flaws.