CVE-2021-33767Public exploit

Enclave code execution via exception reentry

Published Jul 14, 2021 · Updated Aug 10, 2026

Exception-handling reentrancy in Open Enclave SDK 0.1.1 through 0.17.0 allows local users to hijack enclave control flow. The SGX entry path permits an exception immediately after EENTER to return to a malicious host before RSP is initialized, then resumes the enclave on a host-controlled stack. Exploitation requires a host able to interrupt enclave execution and enables enclave-memory disclosure or return-oriented code execution.

CVSS severity8.2
High
EPSS probability0.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Exception-handling reentrancy in Open Enclave SDK 0.1.1 through 0.17.0 allows local users to hijack enclave control flow. The SGX entry path permits an exception immediately after EENTER to return to a malicious host before RSP is initialized, then resumes the enclave on a host-controlled stack. Exploitation requires a host able to interrupt enclave execution and enables enclave-memory disclosure or return-oriented code execution.

The record

CVE
CVE-2021-33767
Published
Jul 14, 2021
Updated
Aug 10, 2026
Vendor
Open Enclave
Product
Open Enclave SDK
Classifications
T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jul 14, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.1.1 <0.17.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Open Enclave · Open Enclave SDKversion=0.1.1 <0.17.1

Published CVSS scores

6.7NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
8.2Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo