CVE-2005-3100 in Security Linux
Summary
by MITRE
Unspecified "PPTP Remote DoS Vulnerability" in Astaro Security Linux 4.027 allows attackers to cause a denial of service.
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Analysis
by VulDB Data Team • 07/26/2017
The vulnerability identified as CVE-2005-3100 represents a critical denial of service weakness within the Point-to-Point Tunneling Protocol implementation of Astaro Security Linux version 4.027. This unspecified flaw specifically targets the remote execution capabilities of the PPTP service, which is commonly employed for establishing virtual private network connections and remote access to corporate networks. The vulnerability arises from inadequate input validation and error handling mechanisms within the PPTP protocol stack, creating opportunities for malicious actors to exploit the system through carefully crafted network packets or connection attempts that trigger unexpected behavior in the network security appliance.
The technical exploitation of this vulnerability occurs through remote network-based attacks that target the PPTP service listening on standard ports, typically 1723 for the control channel and dynamically assigned ports for data channels. Attackers can potentially send malformed packets or trigger specific sequences of PPTP messages that cause the system to enter an unstable state, leading to service disruption, process termination, or complete system reboot. The root cause lies in insufficient validation of incoming PPTP control messages, particularly in how the system handles connection establishment requests, termination commands, or tunnel management operations. This weakness creates a pathway for remote attackers to cause the security appliance to become unresponsive, effectively denying legitimate users access to network services and potentially compromising the availability of critical infrastructure.
The operational impact of this vulnerability extends beyond simple service disruption, as it directly affects the availability and reliability of network security services that organizations depend upon for remote access and secure communications. When exploited successfully, the denial of service condition can lead to extended periods of network unavailability, requiring manual intervention to restore system functionality, including potential system reboots or manual service restarts. The attack surface is particularly concerning for organizations using Astaro Security Linux as their primary network security solution, as the vulnerability affects core network infrastructure components that are essential for maintaining secure remote access capabilities. Network administrators may experience significant downtime and service degradation, potentially affecting business continuity and user productivity while the system remains compromised.
Mitigation strategies for this vulnerability should focus on immediate patch application, network segmentation, and implementation of additional monitoring controls. Organizations should prioritize updating their Astaro Security Linux appliances to versions that address the specific PPTP implementation flaws, as vendor patches typically include enhanced input validation and improved error handling mechanisms. Network administrators should implement firewall rules to restrict access to PPTP ports from trusted networks only, and consider disabling PPTP services entirely if they are not essential for business operations. The implementation of intrusion detection systems with signature-based detection for PPTP-related anomalies can provide early warning capabilities. Additionally, organizations should consider migrating to more secure remote access protocols such as L2TP/IPsec or SSL-based VPN solutions that offer better security guarantees and reduced attack surfaces. This vulnerability aligns with CWE-129, which addresses improper input validation, and maps to ATT&CK technique T1499.004 for network denial of service attacks, highlighting the importance of robust protocol implementation and network security controls.