CVE-2007-6094 in SIParator
Summary
by MITRE
The IPsec module in the VPN component in Ingate Firewall before 4.6.0 and SIParator before 4.6.0 allows remote attackers to cause a denial of service (module crash) via an IPsec Phase 2 proposal that lacks Perfect Forward Secrecy (PFS).
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Analysis
by VulDB Data Team • 09/11/2018
The vulnerability described in CVE-2007-6094 represents a critical flaw in the IPsec module of Ingate Firewall and SIParator products prior to version 4.6.0. This issue specifically targets the VPN component's handling of IPsec Phase 2 proposals, creating a remote denial of service condition that can result in complete module crashes. The vulnerability stems from insufficient validation of IPsec security parameters during the negotiation process, particularly when Perfect Forward Secrecy (PFS) is not properly configured or supported in the Phase 2 proposal. This weakness exposes organizations to potential disruption of their secure communication channels and can be exploited by remote attackers without requiring authentication or privileged access. The flaw aligns with CWE-20, representing a weakness in input validation that allows malformed or incomplete security parameters to cause system instability. From an operational perspective, this vulnerability undermines the reliability of critical network security infrastructure, potentially leaving organizations vulnerable during attack windows when their secure communication channels are most needed.
The technical implementation of this vulnerability occurs within the IPsec protocol handling mechanisms of the affected Ingate products, where the system fails to properly validate the completeness and correctness of Phase 2 proposals before attempting to establish secure connections. When an attacker submits an IPsec Phase 2 proposal that lacks proper Perfect Forward Secrecy parameters, the firewall module encounters an unhandled condition that leads to a crash or module failure. This behavior creates a predictable denial of service scenario where legitimate users cannot establish secure VPN connections while the system remains vulnerable to repeated exploitation attempts. The vulnerability demonstrates poor error handling and defensive programming practices within the IPsec module, as the system does not implement proper fallback mechanisms or graceful degradation when encountering incomplete security proposals. According to ATT&CK framework domain T1499, this represents a denial of service attack technique that specifically targets network infrastructure components, making it particularly dangerous for enterprise security environments where continuous availability is paramount.
Organizations affected by this vulnerability face significant operational risks including disruption of business continuity, potential exposure of sensitive communications, and increased administrative overhead for system recovery and maintenance. The impact extends beyond simple service interruption as it can compromise the overall security posture by creating windows of vulnerability during system restarts or recovery processes. Network administrators must consider the broader implications of this flaw on their security infrastructure, particularly in environments where IPsec-based VPNs serve as primary secure communication channels for remote access, branch office connectivity, or inter-organizational communications. The vulnerability also represents a potential vector for more sophisticated attacks if attackers can leverage the instability to execute additional exploitation techniques or gain unauthorized access to system resources. Mitigation strategies should include immediate deployment of firmware updates to version 4.6.0 or later, implementation of network monitoring to detect unusual connection patterns or system restarts, and establishment of incident response procedures to address potential exploitation attempts. Additionally, organizations should consider implementing redundant secure communication channels and maintaining detailed system logs to track any exploitation attempts that may occur during the remediation process.