CVE-2015-4047 in IPsec-Tools
Summary
by MITRE
racoon/gssapi.c in IPsec-Tools 0.8.2 allows remote attackers to cause a denial of service (NULL pointer dereference and IKE daemon crash) via a series of crafted UDP requests.
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Analysis
by VulDB Data Team • 11/24/2024
The vulnerability identified as CVE-2015-4047 resides within the racoon implementation of IPsec-Tools version 0.8.2, specifically in the gssapi.c file. This flaw represents a critical denial of service vulnerability that can be exploited by remote attackers through carefully crafted UDP packets. The vulnerability manifests as a NULL pointer dereference condition that leads to an immediate crash of the IKE daemon responsible for managing IPsec security associations. The attack vector requires no authentication and can be executed from any remote location capable of sending UDP traffic to the affected system, making it particularly dangerous in network environments where IPsec services are exposed to untrusted networks.
The technical implementation of this vulnerability stems from inadequate input validation within the GSSAPI (Generic Security Services Application Program Interface) processing module of the racoon daemon. When the daemon receives crafted UDP requests containing malformed GSSAPI tokens or security context data, the parsing logic fails to properly validate pointer references before dereferencing them. This fundamental flaw in defensive programming creates a condition where the application attempts to access memory locations that have not been properly initialized or allocated, resulting in an immediate segmentation fault and subsequent daemon termination. The vulnerability aligns with CWE-476 which specifically addresses NULL pointer dereference conditions, and represents a classic example of insufficient input sanitization in security-critical network services.
The operational impact of CVE-2015-4047 extends beyond simple service disruption to potentially compromise network security infrastructure. When the IKE daemon crashes, all active IPsec tunnels managed by that daemon become immediately unavailable, disrupting secure communications between network endpoints. This can lead to cascading failures in network security policies, particularly in environments where IPsec is used for site-to-site VPN connections, remote access, or network segmentation. The vulnerability affects systems running IPsec-Tools 0.8.2 and potentially earlier versions, making it relevant to legacy network security implementations that may not have received timely updates. Organizations relying on this software for secure communications may experience significant service interruptions and potential security gaps during the time between vulnerability discovery and patch deployment.
Mitigation strategies for CVE-2015-4047 should prioritize immediate patching of affected systems with the latest IPsec-Tools version containing the fix. Network administrators should implement defensive measures including UDP port filtering and rate limiting to reduce the effectiveness of potential exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1499.004 which covers network denial of service, and organizations should consider implementing intrusion detection systems to monitor for anomalous UDP traffic patterns that may indicate exploitation attempts. Additionally, network segmentation should be implemented to limit exposure of vulnerable systems to untrusted networks, and regular security assessments should be conducted to identify other potentially vulnerable network security appliances. System administrators should also consider implementing automated monitoring solutions that can detect daemon crashes and automatically initiate restart procedures to minimize service disruption while patches are deployed.