CVE-2002-1997 in ZoneAlarm
Summary
by MITRE
ZoneAlarm Pro 3.0 MailSafe allows remote attackers to bypass filtering and possibly execute arbitrary code via email attachments containing a trailing dot after the file extension.
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Analysis
by VulDB Data Team • 06/11/2018
The vulnerability described in CVE-2002-1997 affects ZoneAlarm Pro 3.0 MailSafe email filtering software, representing a significant security flaw in email attachment handling mechanisms. This issue stems from the software's improper validation of file extensions when processing email attachments, creating a pathway for malicious actors to circumvent security controls. The vulnerability specifically targets the way the software interprets file extensions that contain trailing dots, which is a common technique used in various file system and network security bypass attacks. The flaw demonstrates a classic lack of proper input sanitization and validation that has been documented in numerous security vulnerabilities over the years.
The technical implementation of this vulnerability exploits the inconsistent handling of file extensions by the MailSafe component. When processing email attachments, ZoneAlarm Pro 3.0 fails to properly normalize or validate file extensions that contain trailing dots, allowing attackers to craft malicious attachments that appear legitimate to the filtering system. This behavior creates a condition where the software's file type detection logic is bypassed, potentially enabling the execution of arbitrary code on the target system. The vulnerability operates at the application layer and leverages a fundamental weakness in how the software processes file name extensions, which aligns with common patterns found in buffer overflow and input validation attacks.
The operational impact of this vulnerability extends beyond simple bypassing of email filters to potentially enabling full system compromise. Attackers can exploit this weakness to deliver malicious code through seemingly benign email attachments, making the attack vector particularly dangerous in enterprise environments where email filtering is a primary defense mechanism. The vulnerability can result in unauthorized code execution, data exfiltration, and potential lateral movement within networks, as the compromised system may serve as a launching point for further attacks. This type of vulnerability directly impacts the integrity and confidentiality of email communications, undermining the trust placed in email security solutions.
Security professionals should implement multiple layers of defense to address this vulnerability, including immediate patching of affected ZoneAlarm Pro 3.0 installations and enhanced email filtering policies that validate file extensions more rigorously. The mitigation strategy should incorporate proper input validation techniques that normalize file extensions and reject malformed or suspicious patterns. Organizations should also consider implementing network-based intrusion detection systems to monitor for suspicious email traffic patterns and maintain updated threat intelligence feeds to identify potential exploitation attempts. This vulnerability highlights the importance of proper secure coding practices and input validation, which are fundamental requirements in the secure development lifecycle. The issue demonstrates how seemingly minor implementation flaws can create significant security risks, emphasizing the need for comprehensive security testing and validation of security software components.
This vulnerability relates to several common security weaknesses including CWE-20, which describes improper input validation, and CWE-170, which addresses improper handling of string termination. The attack pattern aligns with techniques documented in the ATT&CK framework under initial access and execution phases, specifically targeting email-based attack vectors. Organizations should also consider implementing email security solutions that employ multiple validation techniques including content inspection, behavioral analysis, and reputation-based filtering to reduce the risk of similar vulnerabilities. The incident underscores the critical importance of thorough testing of security controls and the need for continuous monitoring of security solutions to identify potential bypass mechanisms.