Open Enclave up to 0.19.2 MXCSR Register initialization

Summaryinfo

A vulnerability was found in Open Enclave up to 0.19.2 and classified as problematic. Affected by this vulnerability is an unknown functionality of the component MXCSR Register Handler. Executing a manipulation can lead to initialization. This vulnerability is tracked as CVE-2023-37479. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Open Enclave up to 0.19.2. It has been declared as problematic. This vulnerability affects an unknown code of the component MXCSR Register Handler. The manipulation with an unknown input leads to a initialization vulnerability. The CWE definition for the vulnerability is CWE-665. The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used. The impact remains unknown. CVE summarizes:

Open Enclave is a hardware-agnostic open source library for developing applications that utilize Hardware-based Trusted Execution Environments, also known as Enclaves. There are two issues that are mitigated in version 0.19.3. First, Open Enclave SDK does not properly sanitize the `MXCSR` register on enclave entry. This makes applications vulnerable to MXCSR Configuration Dependent Timing (MCDT) attacks, where incorrect `MXCSR` values can impact instruction retirement by at most one cycle, depending on the (secret) data operand value. Please find more details in the guidance from Intel in the references. Second, Open Enclave SDK does not sanitize x86's alignment check flag `RFLAGS.AC` on enclave entry. This opens up the possibility for a side-channel attacker to be notified for every unaligned memory access performed by the enclave. The issue has been addressed in version 0.19.3 and the current master branch. Users will need to recompile their applications against the patched libraries to be protected from this vulnerability. There are no known workarounds for this vulnerability.

The weakness was disclosed 07/18/2023 as GHSA-5gfr-m6mx-p5w4. The advisory is available at github.com. This vulnerability was named CVE-2023-37479 since 07/06/2023. The technical details are unknown and an exploit is not available.

Upgrading to version 0.19.3 eliminates this vulnerability. Applying the patch ca54623333875b9beaad92c999a92b015c44b079 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Name

• Open Enclave

Version

• 0.19.0
• 0.19.1
• 0.19.2

License

• open-source

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

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