CVE-2020-16166 in Linux
Summary
by MITRE
The Linux kernel through 5.7.11 allows remote attackers to make observations that help to obtain sensitive information about the internal state of the network RNG, aka CID-f227e3ec3b5c. This is related to drivers/char/random.c and kernel/time/timer.c.
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Analysis
by VulDB Data Team • 10/15/2024
The vulnerability identified as CVE-2020-16166 represents a significant information disclosure issue within the Linux kernel version 5.7.11 and earlier. This flaw resides in the kernel's random number generation mechanisms, specifically affecting the network RNG component that is critical for cryptographic security operations. The vulnerability stems from insufficient protection mechanisms that allow remote attackers to observe patterns and make inferences about the internal state of the random number generator, potentially compromising the security of cryptographic operations that depend on unpredictable entropy sources.
The technical implementation of this vulnerability involves the interaction between drivers/char/random.c and kernel/time/timer.c components within the Linux kernel architecture. These modules handle the collection and management of random data from various sources including network traffic patterns, which are essential for maintaining the unpredictability required in cryptographic systems. The flaw enables attackers to perform statistical analysis on network traffic timing and patterns, thereby gaining insights into the internal state of the kernel's random number generator. This information leakage occurs through observable timing differences and network behavior patterns that can be correlated with the internal entropy pool state.
The operational impact of this vulnerability extends beyond simple information disclosure, as it directly affects the security posture of systems relying on kernel-based random number generation for cryptographic operations. Attackers who successfully exploit this vulnerability can potentially reconstruct parts of the random number generator's internal state, which may lead to the prediction of future random values or the compromise of cryptographic keys that depend on these generators. This represents a serious threat to systems handling sensitive data, secure communications, and cryptographic operations that require high entropy sources to maintain their security guarantees. The vulnerability particularly affects systems where network-based random number generation is utilized for generating session keys, cryptographic tokens, or other security-sensitive values.
Mitigation strategies for CVE-2020-16166 should focus on updating to Linux kernel versions 5.7.12 and later, where the vulnerability has been addressed through enhanced protection mechanisms for the random number generator state. Organizations should also implement network monitoring to detect anomalous timing patterns that might indicate exploitation attempts, and consider additional entropy sources to strengthen their cryptographic security posture. The vulnerability aligns with CWE-200, which covers information exposure, and relates to ATT&CK technique T1083 for discovering system information, making it a critical concern for security operations centers monitoring for potential exploitation attempts. System administrators should prioritize patching this vulnerability as part of their regular security maintenance procedures to prevent potential exploitation that could lead to broader compromise of cryptographic systems relying on kernel random number generation.