CVE-2008-5331 in Acrobat
Summary
by MITRE
Adobe Acrobat 9 uses more efficient encryption than previous versions, which makes it easier for attackers to guess a document s password via a brute-force attack.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 06/23/2017
Adobe Acrobat 9 introduced a change in its encryption implementation that inadvertently weakened security measures compared to previous versions. This vulnerability stems from the adoption of a less robust encryption algorithm that reduces the effective entropy of password hashes, making them more susceptible to cryptographic analysis and brute-force attacks. The flaw represents a significant regression in security posture that directly impacts the confidentiality of protected documents.
The technical implementation of this vulnerability lies in how Adobe Acrobat 9 handles password-based encryption for document protection. The software employs a modified encryption scheme that, while appearing more efficient in terms of processing speed, sacrifices cryptographic strength. This change allows attackers to perform more effective brute-force attempts against password-protected documents by reducing the computational complexity required to discover valid passwords through systematic guessing approaches.
From an operational perspective, this vulnerability creates substantial risk for organizations relying on Adobe Acrobat 9 for document security. Attackers can leverage the weakened encryption to systematically test password combinations against protected documents, potentially gaining unauthorized access to sensitive information. The vulnerability affects any document created or modified using Adobe Acrobat 9 with password protection, making it a widespread concern across enterprise environments where document security is paramount. This weakness directly violates the fundamental security principle of maintaining confidentiality through strong encryption mechanisms.
Organizations should immediately implement mitigation strategies including upgrading to newer versions of Adobe Acrobat that restore proper encryption standards, implementing additional access controls beyond password protection, and conducting thorough security assessments of all password-protected documents created with Acrobat 9. The vulnerability demonstrates the critical importance of maintaining cryptographic best practices and avoiding performance optimizations that compromise security. This issue aligns with CWE-310 and ATT&CK techniques related to credential access and cryptanalysis, emphasizing the need for comprehensive security measures beyond basic password protection.
The security implications extend beyond simple document access, as compromised password-protected documents may contain sensitive financial, personal, or proprietary information that could be exploited for identity theft, corporate espionage, or other malicious activities. Organizations must consider the broader threat landscape when addressing this vulnerability and implement layered security approaches that include network monitoring, access logging, and regular security audits to detect potential exploitation attempts. This vulnerability serves as a reminder of the delicate balance between usability and security in cryptographic implementations.