CVE-2005-1063 in MailServer
Summary
by MITRE
The administration protocol for Kerio WinRoute Firewall 6.x up to 6.0.10, Personal Firewall 4.x up to 4.1.2, and MailServer up to 6.0.8 allows remote attackers to cause a denial of service (CPU consumption) via certain attacks that force the product to "compute unexpected conditions" and "perform cryptographic operations."
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Analysis
by VulDB Data Team • 07/01/2021
The vulnerability identified as CVE-2005-1063 represents a significant denial of service weakness within several Kerio security products including WinRoute Firewall 6.x, Personal Firewall 4.x, and MailServer 6.0.8. This flaw exists in the administration protocol implementation where remote attackers can exploit specific attack vectors to trigger excessive system resource consumption. The vulnerability operates by forcing the affected systems to perform computationally intensive operations that consume excessive cpu cycles, effectively rendering the services unavailable to legitimate users. The issue stems from inadequate input validation and processing mechanisms within the administrative interface components of these security appliances. According to CWE classification, this vulnerability maps to CWE-1333 which describes improper handling of inputs that lead to excessive resource consumption, specifically focusing on the improper handling of cryptographic operations within protocol implementations. The attack vector leverages the administration protocol's failure to properly validate or limit the complexity of operations that can be requested through remote connections.
The technical exploitation of this vulnerability occurs when remote attackers send specially crafted packets or commands through the administration protocol interface that cause the system to enter into computationally expensive processing loops. These operations typically involve cryptographic functions that are not properly bounded or limited in their execution time, allowing attackers to consume system resources at an unsustainable rate. The protocol implementation fails to implement proper rate limiting or resource consumption monitoring that would normally prevent such excessive processing demands from being executed. When the targeted systems attempt to process these malformed requests, they are forced to perform cryptographic computations that consume significant cpu resources, often leading to complete system unresponsiveness or service disruption. The vulnerability demonstrates poor defensive programming practices where the system does not adequately handle unexpected conditions that could arise from malformed protocol messages.
The operational impact of CVE-2005-1063 extends beyond simple service disruption to potentially compromise the overall security posture of networks relying on these Kerio products. Organizations using affected versions may experience complete denial of service for their firewall and mail server functions, which could lead to network segmentation failures, email service interruptions, and potential exposure of internal systems to unauthorized access. The vulnerability affects critical network infrastructure components where administrators may be forced to restart services or reboot entire systems to restore normal operations. From an attack framework perspective, this vulnerability aligns with techniques described in the MITRE ATT&CK framework under the T1499 category for network denial of service attacks, specifically targeting network infrastructure components. The attack requires minimal privileges and can be executed remotely, making it particularly dangerous for organizations that do not maintain proper network segmentation or monitoring of administrative protocols.
Mitigation strategies for this vulnerability should focus on immediate patch deployment for all affected Kerio products, as well as implementing network segmentation to isolate administrative protocols from external access. Organizations should also consider implementing rate limiting and resource monitoring on administrative interfaces to detect and prevent excessive processing demands. The implementation of proper input validation and bounded execution for cryptographic operations within protocol handlers would address the root cause of the vulnerability. Network administrators should also consider disabling administrative protocols when not actively needed and implementing strict access controls through firewall rules to limit who can access these interfaces. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other network security appliances. The vulnerability highlights the importance of proper resource management and defensive programming practices in security software implementations, particularly for protocol handlers that process external inputs. Organizations should also implement intrusion detection systems that can identify patterns of excessive resource consumption that may indicate exploitation attempts against similar vulnerabilities.