CVE-2016-4754 in OS X Server
Summary
by MITRE
ServerDocs Server in Apple OS X Server before 5.2 supports the RC4 cipher, which might allow remote attackers to defeat cryptographic protection mechanisms via unspecified vectors.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/21/2022
The vulnerability identified as CVE-2016-4754 affects Apple OS X Server versions prior to 5.2, specifically within the ServerDocs component that handles document sharing services. This issue represents a significant cryptographic weakness that undermines the security posture of affected systems. The vulnerability stems from the server's support for the RC4 cipher suite, a cryptographic algorithm that has been widely deprecated due to its inherent weaknesses and susceptibility to various attack vectors. The RC4 cipher was originally designed to provide strong encryption but has since been proven vulnerable to several cryptographic attacks including bias attacks and key recovery techniques that can compromise the confidentiality of encrypted communications.
The technical flaw in ServerDocs Server manifests through the implementation of RC4 cipher support within its secure communication protocols, particularly affecting HTTPS and other encrypted services that rely on this outdated cryptographic method. This weakness allows remote attackers to potentially exploit the cryptographic protection mechanisms by leveraging known vulnerabilities in RC4's keystream generation process. The unspecified vectors mentioned in the description suggest that attackers could exploit this weakness through various attack surfaces including man-in-the-middle scenarios, session hijacking attempts, or by performing cryptographic analysis on captured traffic to recover sensitive information. The vulnerability falls under the CWE-327 weakness category, which specifically addresses the use of weak cryptographic algorithms, and aligns with ATT&CK technique T1566 related to credential harvesting through various attack vectors.
The operational impact of this vulnerability extends beyond simple cryptographic weakness, as it creates opportunities for attackers to compromise sensitive data transmitted through the affected server services. Organizations relying on Apple OS X Server for document sharing, web hosting, or other services that utilize HTTPS encryption face potential exposure to data interception, credential theft, and unauthorized access to confidential information. The risk is particularly elevated in environments where sensitive corporate data, personal information, or intellectual property is stored and accessed through these services. Attackers could potentially decrypt communications, impersonate legitimate users, or gain unauthorized access to server resources that rely on the compromised cryptographic protection mechanisms.
Organizations should immediately implement mitigations including upgrading to Apple OS X Server version 5.2 or later, which removes support for RC4 cipher suites and addresses the cryptographic weakness. System administrators should also review and disable any remaining RC4 cipher support in related services, configure stronger cryptographic protocols such as TLS 1.2 with modern cipher suites, and implement network monitoring to detect potential exploitation attempts. Additionally, organizations should conduct comprehensive security assessments of their server configurations, review certificate management practices, and ensure all systems are updated with the latest security patches. The remediation process should include verification that RC4 cipher suites are completely disabled in all network services, particularly those that handle sensitive data transfers, and implementation of proper logging and alerting mechanisms to detect potential cryptographic attacks against the server infrastructure.