7.5
HIGH
CVE-2023-37479
Open Enclave MXCSR and RFLAGS AC Unsanitizeable Registers Information Disclosure and Side-Channel Vulnerability
Description

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.

INFO

Published Date :

July 17, 2023, 11:15 p.m.

Last Modified :

Nov. 21, 2024, 8:11 a.m.

Remotely Exploitable :

Yes !

Impact Score :

3.6

Exploitability Score :

3.9
Affected Products

The following products are affected by CVE-2023-37479 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Openenclave openenclave

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2023-37479 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2023-37479 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://github.com/openenclave/openenclave/commit/ca54623333875b9beaad92c999a92b015c44b079
    Added Reference https://github.com/openenclave/openenclave/security/advisories/GHSA-5gfr-m6mx-p5w4
    Added Reference https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/best-practices/mxcsr-configuration-dependent-timing.html
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Initial Analysis by [email protected]

    Jul. 28, 2023

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
    Changed Reference Type https://github.com/openenclave/openenclave/commit/ca54623333875b9beaad92c999a92b015c44b079 No Types Assigned https://github.com/openenclave/openenclave/commit/ca54623333875b9beaad92c999a92b015c44b079 Patch
    Changed Reference Type https://github.com/openenclave/openenclave/security/advisories/GHSA-5gfr-m6mx-p5w4 No Types Assigned https://github.com/openenclave/openenclave/security/advisories/GHSA-5gfr-m6mx-p5w4 Vendor Advisory
    Changed Reference Type https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/best-practices/mxcsr-configuration-dependent-timing.html No Types Assigned https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/best-practices/mxcsr-configuration-dependent-timing.html Technical Description
    Added CPE Configuration OR *cpe:2.3:a:openenclave:openenclave:*:*:*:*:*:*:*:* versions up to (excluding) 0.19.3
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2023-37479 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2023-37479 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.11 }} 0.01%

score

0.44414

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
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Scope
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