CVE-2020-24512 in Intel
Summary
by MITRE • 06/10/2021
Observable timing discrepancy in some Intel(R) Processors may allow an authenticated user to potentially enable information disclosure via local access.
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Analysis
by VulDB Data Team • 06/12/2021
This vulnerability represents a sophisticated side-channel attack vector that exploits timing discrepancies in Intel processor architectures, specifically targeting the instruction execution behavior that can reveal sensitive information through observable delays. The flaw exists within the processor's microarchitecture where certain operations exhibit variable execution times based on data values, creating measurable timing differences that can be exploited by malicious actors. This timing variation occurs during cryptographic operations and memory access patterns, allowing attackers to infer confidential information through careful analysis of execution time differences. The vulnerability is particularly concerning because it operates at the hardware level and can be leveraged by authenticated users with local access to the affected system, making it a significant threat in environments where privilege escalation is possible.
The technical implementation of this vulnerability stems from the processor's handling of specific instruction sequences where the execution time varies depending on the values being processed. This behavior is particularly evident in operations involving memory access, branch prediction, and cryptographic algorithms where the processor's internal mechanisms may take different paths based on data content. The timing discrepancies can be measured using high-resolution timers and statistical analysis techniques, enabling attackers to reconstruct sensitive data such as encryption keys, passwords, or other confidential information. This type of vulnerability falls under the broader category of timing side-channel attacks that have been extensively documented in cybersecurity literature and are classified as CWE-203 in the CWE database. The attack requires an authenticated local user because direct hardware manipulation is not possible, but the attacker can leverage existing system access to perform repeated measurements and statistical analysis.
The operational impact of CVE-2020-24512 extends beyond simple information disclosure, as it can potentially compromise the confidentiality of cryptographic keys and sensitive data stored in memory or processed by the affected processors. Attackers can utilize this vulnerability to perform cache timing attacks, branch prediction attacks, or other timing-based reconnaissance techniques that can reveal information about the system's internal state. The vulnerability affects multiple Intel processor generations and is particularly dangerous in virtualized environments where multiple tenants share the same physical hardware, as timing information from one virtual machine could potentially leak to others. This type of attack aligns with techniques documented in the MITRE ATT&CK framework under the T1059 and T1082 tactics, specifically targeting system information discovery and privilege escalation capabilities. Organizations running critical infrastructure or handling sensitive data are particularly vulnerable to this attack vector, as it can be used to extract confidential information from systems that may appear secure from traditional attack vectors.
Mitigation strategies for this vulnerability involve a combination of software patches, microcode updates, and architectural modifications. Intel has released microcode updates to address the timing discrepancies in affected processors, which typically involve modifying the processor's branch prediction algorithms and memory access patterns to eliminate the variable timing behavior. System administrators should ensure all affected systems receive the latest microcode updates and security patches from Intel, while also implementing additional software-level protections such as constant-time algorithm implementations and randomization techniques. Operating system vendors have also released updates that include mitigations for timing side-channel attacks, including kernel-level protections and runtime environment modifications that reduce the observability of timing variations. Organizations should consider implementing additional security controls such as monitoring for unusual timing patterns, restricting local access privileges, and deploying intrusion detection systems that can identify potential timing-based attacks. The vulnerability highlights the importance of considering side-channel attack vectors in security assessments and the need for comprehensive security architectures that address both traditional and advanced persistent threats.