CVE-2005-0109 in Solaris
Summary
by MITRE
Hyper-Threading technology, as used in FreeBSD and other operating systems that are run on Intel Pentium and other processors, allows local users to use a malicious thread to create covert channels, monitor the execution of other threads, and obtain sensitive information such as cryptographic keys, via a timing attack on memory cache misses.
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Analysis
by VulDB Data Team • 01/12/2025
The vulnerability described in CVE-2005-0109 represents a significant security weakness in modern processor architectures that leverage hyper-threading technology. This flaw specifically affects FreeBSD and other operating systems running on Intel Pentium processors and similar architectures that implement hyper-threading capabilities. The vulnerability stems from the fundamental design of hyper-threading where multiple execution threads share the same physical processor core, including critical resources such as the memory cache hierarchy. When multiple threads execute concurrently on the same core, they compete for access to the shared cache, creating observable timing variations that can be exploited by malicious actors.
The technical implementation of this vulnerability exploits the cache timing attack mechanism that occurs when threads share the same execution unit. In hyper-threaded processors, the memory cache is a shared resource between logical processors, meaning that when one thread accesses data in the cache, it affects the cache state for other threads running on the same physical core. An attacker can manipulate their malicious thread to monitor cache access patterns of target threads by measuring the time differences between cache hits and cache misses. This timing information reveals patterns that can be correlated with sensitive data operations, particularly cryptographic functions that exhibit characteristic cache access patterns during key operations.
The operational impact of this vulnerability extends beyond simple information disclosure to represent a serious threat to cryptographic security and system integrity. Attackers can leverage this weakness to extract cryptographic keys, passwords, and other sensitive information from running processes that are not directly accessible through conventional means. The covert channel established through this timing attack allows persistent monitoring of target threads, making it particularly dangerous for systems handling confidential data. The vulnerability affects the confidentiality and integrity aspects of the CIA triad, as it enables unauthorized information extraction without direct system compromise or privilege escalation.
Mitigation strategies for this vulnerability involve several approaches that address the fundamental architectural issue. Operating system vendors can implement kernel-level protections such as disabling hyper-threading entirely, which eliminates the shared cache resource that enables the attack. Additionally, software-level mitigations include cache flushing mechanisms and timing randomization techniques that obscure the cache access patterns from attackers. System administrators should consider disabling hyper-threading on systems handling sensitive cryptographic operations, particularly in environments where the risk of cache timing attacks is elevated. The vulnerability aligns with CWE-203, which describes "Observable Behavior Difference" and represents a class of weaknesses where differences in system behavior can be observed and exploited by attackers. This weakness falls under the ATT&CK technique T1059.001 for "Command and Scripting Interpreter" and T1566 for "Phishing" when considering the broader attack surface that such vulnerabilities create. Organizations should also implement proper security controls such as regular vulnerability assessments, access controls, and monitoring systems to detect potential exploitation attempts. The remediation approach must balance security requirements with performance considerations, as disabling hyper-threading can significantly impact system throughput and resource utilization.