HOMEVULNERABILITIESCVE-2021-43323
HIGH

CVE-2021-43323

NVD-CWE-noinfoPublished: February 3, 2022· Updated: Jun 17, 2026

8.2
CVSS v3.1

Official Description

An issue was discovered in UsbCoreDxe in Insyde InsydeH2O with kernel 5.5 before 05.51.45, 5.4 before 05.43.45, 5.3 before 05.35.45, 5.2 before 05.26.45, 5.1 before 05.16.45, and 5.0 before 05.08.45. An SMM callout vulnerability allows an attacker to hijack execution flow of code running in System Management Mode. Exploiting this issue could lead to escalating privileges to SMM.

NVD Source

Technical Analysis

CVE-2021-43323 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.2.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.High
User InteractionNone
ScopeChanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Affected Vendors & Products

insyde1 product(s)
insydeh2o
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf
ADVISORYhttps://security.netapp.com/advisory/ntap-20220217-0013/
ADVISORYhttps://www.insyde.com/security-pledge
ADVISORYhttps://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf
ADVISORYhttps://security.netapp.com/advisory/ntap-20220217-0013/
ADVISORYhttps://www.insyde.com/security-pledge

All References (7)

→
https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdfThird Party Advisory
→
https://security.netapp.com/advisory/ntap-20220217-0013/Third Party Advisory
→
https://www.insyde.com/security-pledgeVendor Advisory
→
https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdfThird Party Advisory
→
https://security.netapp.com/advisory/ntap-20220217-0013/Third Party Advisory
→
https://www.insyde.com/security-pledgeVendor Advisory
→
https://www.kb.cert.org/vuls/id/796611

Quick Facts

CVE IDCVE-2021-43323
CVSS Score8.2 / 10
SeverityHIGH
WeaknessNVD-CWE-noinfo
CISA KEVNo
Affected1 vendor(s)
PublishedFeb 3, 2022

Related CVEs (NVD-CWE-noinfo)

CVE-2012-3859
10.0
CVE-2011-0807
10.0
CVE-2024-22216
10.0
CVE-2023-45894
10.0
CVE-2014-2623
10.0
CVE-2007-5108
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-43323 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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