CVE-2003-1376 in WinZip
Summary
by MITRE
WinZip 8.0 uses weak random number generation for password protected ZIP files, which allows local users to brute force the encryption keys and extract the data from the zip file by guessing the state of the stream coder.
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Analysis
by VulDB Data Team • 06/07/2017
The vulnerability identified as CVE-2003-1376 represents a critical weakness in the cryptographic implementation of WinZip 8.0's password protection mechanism. This flaw stems from the application's reliance on a pseudorandom number generator that lacks sufficient entropy and cryptographic strength to produce secure encryption keys for password-protected archive files. The vulnerability specifically affects the random number generation algorithm used during the encryption process, creating predictable patterns that can be exploited by malicious actors. According to CWE-330, this represents a use of weak entropy source, which directly undermines the security foundation of the encryption system. The implementation fails to meet the minimum requirements for cryptographic randomness as defined by industry standards and best practices.
The technical exploitation of this vulnerability occurs through brute force attacks that target the predictable nature of the random number stream used in WinZip 8.0's encryption algorithm. Attackers can analyze the encryption stream and deduce the internal state of the pseudorandom number generator, effectively reverse-engineering the encryption keys needed to access protected archive contents. This approach leverages the predictable sequence generation inherent in weak random number generators, allowing unauthorized users to systematically guess the encryption parameters without requiring extensive computational resources or advanced cryptographic techniques. The vulnerability operates at the application layer and can be classified under ATT&CK technique T1552.001, which covers unsecured credentials and credential access through predictable encryption keys.
The operational impact of this vulnerability extends beyond simple unauthorized data access, as it fundamentally compromises the confidentiality assurances provided by password protection mechanisms. Local users who can access the system and analyze the encrypted archives can exploit this weakness to extract sensitive information without requiring the original password. This creates a significant risk for organizations relying on WinZip 8.0 for data protection, as the vulnerability allows for data recovery without proper authorization. The attack vector is particularly concerning because it does not require network connectivity or complex exploitation techniques, making it accessible to attackers with basic technical knowledge. The vulnerability affects any system running WinZip 8.0 where password-protected archives have been created, potentially exposing large volumes of sensitive data that should have been protected through encryption.
Mitigation strategies for CVE-2003-1376 require immediate action to address the underlying cryptographic weakness in WinZip 8.0. Organizations should upgrade to newer versions of WinZip that implement stronger random number generation algorithms and meet current cryptographic standards for encryption key generation. The most effective remediation involves replacing the vulnerable software with a version that uses cryptographically secure pseudorandom number generators and adheres to established encryption protocols. Additionally, system administrators should conduct comprehensive audits of all systems containing vulnerable WinZip installations and ensure that existing password-protected archives are re-encrypted using secure methods. This vulnerability demonstrates the critical importance of proper entropy sources in cryptographic implementations and highlights the need for regular security assessments of encryption tools to prevent similar weaknesses from persisting in software applications.