CVE-2019-0122 in SGX SDK
Summary
by MITRE
Double free in Intel(R) SGX SDK for Linux before version 2.2 and Intel(R) SGX SDK for Windows before version 2.1 may allow an authenticated user to potentially enable information disclosure or denial of service via local access.
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Analysis
by VulDB Data Team • 05/16/2020
The vulnerability identified as CVE-2019-0122 represents a critical double free error within Intel Software Guard Extensions SDK implementations across both Linux and Windows platforms. This flaw exists in versions prior to 2.2 for Linux and 2.1 for Windows, affecting the core memory management functions of the Intel SGX software development kit. The vulnerability stems from improper handling of memory allocation and deallocation sequences within the SDK's runtime libraries, creating conditions where the same memory block could be freed twice. Such a condition typically occurs when developers fail to properly track memory state or when error handling routines contain logic flaws that cause multiple deallocation calls to the same memory address.
The technical exploitation of this vulnerability requires an authenticated user with local access to the system, as the double free condition manifests during the execution of SGX enclave applications. When the SDK processes memory management operations for enclave code, particularly during error recovery or cleanup sequences, the improper memory handling causes the system to free the same memory region twice. This can result in memory corruption that may be leveraged to either disclose sensitive information stored in memory or cause system instability leading to denial of service conditions. The vulnerability specifically impacts the memory management subsystem of the Intel SGX SDK, which is responsible for handling enclave creation, execution, and destruction phases.
From an operational perspective, this vulnerability poses significant risks to systems utilizing Intel SGX technology for confidential computing workloads. The potential for information disclosure is particularly concerning as it could expose sensitive data processed within SGX enclaves, undermining the fundamental security guarantees that Intel SGX is designed to provide. The denial of service aspect threatens system availability, potentially causing legitimate applications to crash or become unresponsive. Organizations deploying SGX-based solutions must consider the impact on their security posture, as this vulnerability could allow attackers to compromise the integrity of confidential computing environments. The local access requirement limits the attack surface but does not eliminate the threat, especially in multi-tenant environments where privilege escalation is possible.
Mitigation strategies for CVE-2019-0122 primarily involve upgrading to the patched versions of Intel SGX SDK, specifically version 2.2 for Linux and 2.1 for Windows. Organizations should implement comprehensive patch management procedures to ensure all systems utilizing Intel SGX technology are updated promptly. Additional defensive measures include monitoring for unusual memory allocation patterns and implementing strict access controls to minimize the risk of unauthorized local access. Security teams should also conduct thorough code reviews of applications built using the affected SDK versions to identify potential exploitation vectors. The vulnerability aligns with CWE-415, which describes double free conditions in memory management, and represents a variant of memory corruption vulnerabilities that can be exploited through the ATT&CK technique of privilege escalation and code injection. System administrators should maintain detailed logging of enclave operations and memory management activities to detect potential exploitation attempts.