CVE-2001-1540 in IPRoute
Summary
by MITRE
IPRoute 0.973, 0.974 and 1.18 allows remote attackers to cause a denial of service via fragmented IP packets that split the TCP header.
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Analysis
by VulDB Data Team • 06/05/2018
The vulnerability identified as CVE-2001-1540 affects IPRoute versions 0.973, 0.974, and 1.18, representing a significant denial of service weakness in network routing software. This issue stems from the improper handling of fragmented IP packets that specifically target TCP headers within the routing infrastructure. The vulnerability operates at the network layer of the OSI model, exploiting fundamental packet processing mechanisms that are critical for proper network operation.
The technical flaw manifests when the affected IPRoute software encounters fragmented IP packets where the fragment boundaries occur within the TCP header portion of the packet. This particular scenario causes the routing software to fail in properly reconstructing the original TCP packet, leading to system instability and potential complete service disruption. The implementation does not adequately validate fragment boundaries or properly handle TCP header fragmentation, creating a condition where legitimate network traffic can be exploited to trigger system crashes or unresponsive states.
From an operational perspective, this vulnerability presents a severe risk to network infrastructure that relies on IPRoute for routing decisions. Attackers can exploit this weakness by crafting malicious fragmented packets that specifically split TCP headers across fragment boundaries, causing the affected systems to consume excessive resources or enter unstable states. The impact extends beyond simple service interruption as the vulnerability can potentially lead to complete system crashes, requiring manual intervention and system restarts. This makes it particularly dangerous in environments where continuous network availability is critical, such as enterprise networks, data centers, or service provider infrastructures.
The vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and represents a classic example of how network protocol implementation flaws can create denial of service conditions. From an attack framework perspective, this vulnerability maps to ATT&CK technique T1498, specifically targeting network denial of service by exploiting weaknesses in network infrastructure components. The attack requires minimal sophistication to execute, as it only requires sending properly crafted fragmented packets, making it a preferred method for attackers seeking to disrupt network services without requiring advanced technical skills or significant resources.
Mitigation strategies should focus on immediate patching of affected IPRoute versions to address the fragment handling logic and implement proper TCP header validation. Network administrators should consider implementing ingress filtering and packet validation rules at network boundaries to prevent malicious fragmented packets from reaching vulnerable systems. Additionally, monitoring systems should be configured to detect unusual packet fragmentation patterns that may indicate exploitation attempts. The implementation of intrusion detection systems with signature-based detection for this specific vulnerability pattern would provide early warning capabilities. Organizations should also consider network segmentation to limit the impact scope and implement redundant routing systems to maintain service availability during potential exploitation attempts.