CVE-2021-0127 in Intel
Summary
by MITRE • 02/10/2022
Insufficient control flow management in some Intel(R) Processors may allow an authenticated user to potentially enable a denial of service via local access.
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Analysis
by VulDB Data Team • 02/14/2022
This vulnerability resides within Intel processors and represents a control flow management weakness that could be exploited by authenticated users with local access to cause denial of service conditions. The issue stems from inadequate handling of control flow instructions within the processor's microarchitecture, creating potential pathways for malicious code execution or system instability. The vulnerability affects Intel processors that implement specific control flow instructions and may manifest when the processor encounters certain instruction sequences that are not properly managed by the control flow engine. Security researchers identified that the processor's handling of conditional branches, indirect jumps, and other control flow related operations does not adequately prevent certain malformed instruction patterns from causing unexpected behavior.
The technical flaw manifests through improper control flow management during instruction execution, where the processor's branch prediction mechanisms or control flow validation routines fail to properly validate or handle specific instruction combinations. This weakness allows an authenticated local user to craft sequences of instructions that can cause the processor to enter an inconsistent state, potentially leading to system hangs, crashes, or denial of service conditions. The vulnerability does not require network access or remote exploitation, making it particularly concerning for environments where local authentication is possible. The issue affects multiple generations of Intel processors and can be triggered through normal system operation when specific control flow patterns are encountered.
The operational impact of this vulnerability extends beyond simple denial of service as it can potentially disrupt critical system operations and compromise overall system reliability. When exploited, the vulnerability may cause applications to crash, system services to become unavailable, or in severe cases, result in complete system lockups. The authenticated nature of the exploit means that any user with local access to the system could potentially trigger the condition, making it a significant concern for multi-user systems or environments where privilege escalation is possible. Organizations running Intel-based systems may experience unexpected service interruptions, particularly in mission-critical applications where system stability is paramount.
Mitigation strategies for this vulnerability should focus on both software and firmware updates from Intel along with operational security measures. System administrators should prioritize applying the latest processor microcode updates and firmware patches provided by Intel to address the control flow management issues. Additionally, implementing strict access controls and monitoring for unusual system behavior can help detect potential exploitation attempts. The vulnerability aligns with CWE-699 - Object Management and ATT&CK technique T1499.004 - Endpoint Denial of Service to understand the broader threat landscape. Organizations should also consider implementing runtime monitoring solutions that can detect anomalous control flow patterns and alert security teams to potential exploitation attempts. Regular security assessments and vulnerability scanning should include verification of processor microcode versions to ensure complete protection against this and similar control flow related vulnerabilities.