PT-2023-25989 · Unknown · Open Enclave

David Oswald + 4 · Published 2023-07-17 · Updated 2023-07-28 · CVE-2023-37479

Positive Technologies (AI Summary)

CVSS v3.1

5.3

Medium

Base vector

AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

Name of the Vulnerable Software and Affected Versions Open Enclave versions prior to 0.19.3

Description The issue concerns two problems in the Open Enclave SDK. First, it does not properly sanitize the MXCSR register on enclave entry, making applications vulnerable to MXCSR Configuration Dependent Timing (MCDT) attacks. This could impact instruction retirement by at most one cycle, depending on the secret data operand value. Second, the SDK does not sanitize x86's alignment check flag RFLAGS.AC on enclave entry, allowing a side-channel attacker to be notified for every unaligned memory access performed by the enclave.

Recommendations For versions prior to 0.19.3, update to version 0.19.3 or later and recompile applications against the patched libraries to be protected from this issue. As a temporary workaround, consider restricting access to sensitive data and minimizing unaligned memory accesses until the update can be applied.

Exploit

Fix

Improper Initialization

Weakness Enumeration

CWE-665

Related Identifiers

CVE-2023-37479

GHSA-5GFR-M6MX-P5W4

Affected Products

Open Enclave

References · 6

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/37xxx/CVE-2023-37479.json · Exploit
• https://github.com/openenclave/openenclave/commit/ca54623333875b9beaad92c999a92b015c44b079 · Patch
• https://github.com/openenclave/openenclave/security/advisories/GHSA-5gfr-m6mx-p5w4 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2023-37479 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2023-37479 · Security Note
• https://intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/best-practices/mxcsr-configuration-dependent-timing.html · Note