CVE-2004-0037 in Firstclass Desktop Client
Summary
by MITRE
FirstClass Desktop Client 7.1 allows remote attackers to execute arbitrary commands via hyperlinks in FirstClass RTF messages.
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Analysis
by VulDB Data Team • 07/05/2017
The vulnerability identified as CVE-2004-0037 represents a critical remote code execution flaw in the FirstClass Desktop Client version 7.1 that specifically affects the handling of rich text format messages. This vulnerability stems from the client application's insufficient validation of hyperlink content within RTF messages, creating a pathway for malicious actors to execute arbitrary commands on affected systems. The flaw exists in the client-side message processing functionality where hyperlinks embedded in RTF formatted messages are not properly sanitized before being processed, allowing attackers to craft malicious content that can trigger unintended system behavior when the message is opened.
The technical implementation of this vulnerability falls under the category of insecure deserialization and input validation failures, which aligns with CWE-20 - Improper Input Validation and CWE-94 - Improper Control of Generation of Code. When a user opens a malicious RTF message containing specially crafted hyperlinks, the client application attempts to process these links without adequate security checks, potentially executing malicious code with the privileges of the user running the application. The vulnerability is particularly dangerous because it leverages social engineering techniques through email messages, making it difficult for users to distinguish between legitimate and malicious content.
The operational impact of this vulnerability extends beyond simple command execution, as it provides attackers with the ability to gain full system access, install malware, modify system configurations, or exfiltrate sensitive data. Attackers can exploit this vulnerability by embedding malicious hyperlinks within RTF documents that, when clicked, execute shell commands or download additional malicious payloads. The attack surface is broad since FirstClass Desktop Client was commonly used in enterprise environments, making organizations particularly vulnerable to targeted attacks. This vulnerability also demonstrates the risks associated with rich text processing in client applications, where the complexity of parsing formatted content can introduce security gaps that are difficult to detect and remediate.
Mitigation strategies for CVE-2004-0037 should include immediate application of vendor patches, network-level filtering of RTF content, and user education regarding the dangers of opening untrusted RTF messages. Organizations should implement strict email content filtering policies that block or quarantine RTF attachments from unknown sources. The ATT&CK framework categorizes this vulnerability under T1203 - Exploitation for Client Execution, highlighting the importance of defending against client-side exploitation techniques. Additionally, system administrators should consider implementing application whitelisting policies that restrict the execution of potentially malicious commands and monitor for unusual command execution patterns that might indicate exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify any similar weaknesses in other client applications that might be susceptible to similar exploitation techniques.