CVE-2002-0208 in PGPfire
Summary
by MITRE
PGP Security PGPfire 7.1 for Windows alters the system s TCP/IP stack and modifies packets in ICMP error messages in a way that allows remote attackers to determine that the system is running PGPfire.
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Analysis
by VulDB Data Team • 06/06/2018
This vulnerability in PGP Security PGPfire 7.1 for Windows represents a significant information disclosure flaw that undermines network security through protocol manipulation. The software fundamentally alters the TCP/IP stack behavior by modifying ICMP error messages, creating a covert channel that reveals system identification information. This modification occurs at the network protocol level, where legitimate ICMP error packets are altered to include identifiable signatures that indicate the presence of PGPfire software, thereby exposing the system configuration to potential attackers.
The technical implementation of this vulnerability involves the modification of ICMP error message processing within the Windows TCP/IP stack. When network packets are dropped or fail to reach their destination, ICMP error messages are generated to notify the source system. PGPfire 7.1 intercepts these messages and alters their content to include specific markers that identify the system as running PGPfire software. This manipulation occurs at the kernel level of the TCP/IP stack, making it particularly insidious as it operates below the application layer where most security monitoring occurs. The modification process essentially creates a fingerprint that attackers can detect through network analysis, effectively revealing the presence of the security software.
The operational impact of this vulnerability extends beyond simple information disclosure to create a significant attack surface that can be exploited by threat actors. Remote attackers who can observe ICMP traffic can identify systems running PGPfire 7.1, which provides them with valuable intelligence for targeting specific vulnerabilities associated with that particular security software. This information can be leveraged in conjunction with other reconnaissance techniques to develop more sophisticated attack strategies. The vulnerability essentially creates a backdoor of sorts, where the very security measures designed to protect the system inadvertently reveal its presence to potential attackers.
From a cybersecurity perspective, this vulnerability aligns with CWE-200 (Information Exposure) and demonstrates how security tools themselves can become attack vectors when improperly implemented. The ATT&CK framework categorizes this behavior under reconnaissance techniques, specifically T1592 (Gather Victim Host Information) and T1046 (Network Service Scanning), as it enables attackers to identify system characteristics and security implementations. The modification of ICMP error messages represents a form of protocol manipulation that bypasses traditional network security monitoring, as these altered packets appear legitimate to standard network inspection tools. Organizations using PGPfire 7.1 for Windows face a unique challenge where their security infrastructure becomes a liability rather than a protection mechanism.
The recommended mitigations for this vulnerability involve immediate software updates from PGP Security to address the TCP/IP stack modifications and ICMP handling behavior. System administrators should implement network monitoring to detect anomalous ICMP traffic patterns that might indicate the presence of this vulnerability. Additionally, organizations should consider network segmentation and firewall rules that limit ICMP traffic to prevent unauthorized observation of these modified packets. The vulnerability also underscores the importance of conducting thorough security assessments of all network security tools to ensure they do not introduce new attack vectors. Regular network audits should include checks for unusual ICMP behavior and modifications to standard protocol handling that could indicate similar vulnerabilities in other security software implementations.