CVE-2002-1696 in PGP
Summary
by MITRE
Microsoft Outlook plug-in PGP version 7.0, 7.0.3, and 7.0.4 silently saves a decrypted copy of a message to hard disk when "Automatically decrypt/verify when opening messages" option is checked, "Always use Secure Viewer when decrypting" option is not checked, and the user replies to an encrypted message.
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Analysis
by VulDB Data Team • 06/09/2018
This vulnerability exists in Microsoft Outlook plug-in PGP version 7.0, 7.0.3, and 7.0.4 where a security flaw allows for unauthorized data exposure through silent file creation on the local system. The issue manifests when specific user configuration settings are enabled, creating a dangerous scenario where encrypted messages are automatically decrypted and stored without user awareness or explicit consent. The vulnerability is particularly concerning because it operates entirely in the background without any user notification or prompt, making it difficult to detect and potentially exploitable by malicious actors who might monitor system files for sensitive information.
The technical implementation flaw stems from the plug-in's handling of message decryption processes when the "Automatically decrypt/verify when opening messages" option is enabled. When users reply to encrypted messages, the system silently creates decrypted copies of the message content on the local hard disk, bypassing normal security protocols that would typically require explicit user confirmation for such operations. This behavior violates fundamental security principles by creating plaintext copies of sensitive information without proper authorization mechanisms. The vulnerability is classified under CWE-200, which deals with Information Exposure, and represents a significant weakness in the system's security architecture.
The operational impact of this vulnerability is substantial as it creates persistent plaintext copies of encrypted messages on the user's local storage system. These decrypted files remain accessible to anyone with access to the local system, including unauthorized users, malware, or compromised accounts. The risk is particularly elevated in shared computing environments, public computers, or systems where users have multiple accounts or where system administrators might have access to user directories. Attackers could potentially exploit this vulnerability by monitoring the local file system for recently created files or by using automated tools to scan for decrypted message copies that may contain sensitive business information, personal data, or confidential communications.
This vulnerability directly relates to ATT&CK technique T1566 which involves credential access through social engineering and system compromise, as the silent creation of plaintext copies creates additional attack vectors for data exfiltration. The flaw also connects to T1074 which covers data staging and collection, as the system unintentionally creates copies of sensitive information that can be harvested by attackers. Organizations using affected PGP versions face increased risk of data breaches, compliance violations, and potential legal consequences due to the unauthorized storage of encrypted message contents. The vulnerability represents a critical weakness in the principle of least privilege and data protection, as it allows for automatic data duplication without proper access controls or user awareness. Mitigation strategies should include immediate patching of the affected PGP versions, disabling the automatic decryption feature, implementing strict access controls on local storage systems, and monitoring for unauthorized file creation activities. Additionally, organizations should consider implementing endpoint detection and response solutions that can identify and alert on suspicious file creation patterns that may indicate exploitation of this vulnerability.