CVE-2006-4408 in Mac OS X
Summary
by MITRE
The Security Framework in Apple Mac OS X 10.4 through 10.4.8 allows remote attackers to cause a denial of service (resource consumption) via certain public key values in an X.509 certificate that requires extra resources during signature verification. NOTE: this issue may be similar to CVE-2006-2940.
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Analysis
by VulDB Data Team • 06/15/2025
The vulnerability described in CVE-2006-4408 represents a significant security flaw within Apple Mac OS X versions 10.4 through 10.4.8, specifically targeting the operating system's security framework. This issue manifests as a denial of service condition that can be triggered remotely through manipulation of X.509 certificates, particularly those containing specific public key values that demand excessive computational resources during the signature verification process. The security framework in these macOS versions fails to properly handle certain cryptographic operations that would normally be processed efficiently, creating a potential attack vector where malicious actors can consume system resources at an unsustainable rate.
The technical root cause of this vulnerability lies in the insufficient resource management and validation mechanisms within the X.509 certificate processing subsystem of the security framework. When the system encounters public key values that require additional computational overhead during signature verification, the cryptographic libraries fail to implement proper resource limits or early termination conditions. This allows attackers to craft malicious certificates containing specially constructed public key parameters that cause the verification process to consume disproportionate amounts of CPU cycles and memory resources. The flaw operates at the cryptographic protocol level, specifically affecting how the system handles public key operations during certificate validation, which aligns with CWE-778, which addresses insufficient logging of critical events and resource consumption issues.
The operational impact of this vulnerability extends beyond simple service disruption, as it can potentially lead to system instability and resource exhaustion that affects legitimate users and applications. Attackers can leverage this weakness by presenting malicious certificates to systems running vulnerable macOS versions, causing the security framework to enter resource-intensive processing states that may eventually result in system crashes or unresponsiveness. The attack requires minimal privileges since it operates at the certificate validation level, making it particularly dangerous as it can be exploited through various network-based interactions where certificates are processed automatically. This vulnerability directly relates to the ATT&CK technique T1499.004, which involves resource exhaustion attacks targeting system availability.
Mitigation strategies for CVE-2006-4408 require immediate system updates to patched versions of macOS, as Apple released security updates addressing this specific issue in subsequent releases. Organizations should also implement certificate validation policies that limit the scope of certificate processing and establish monitoring for unusual resource consumption patterns during cryptographic operations. Network administrators should consider implementing certificate filtering mechanisms to prevent the acceptance of certificates with suspicious public key parameters, while system administrators should ensure that all macOS systems are updated to versions that contain the necessary security patches. The vulnerability demonstrates the importance of proper resource management in cryptographic implementations and highlights the need for robust input validation in security frameworks, particularly when processing external data such as certificates that may contain maliciously crafted elements designed to exploit implementation weaknesses.