Security readout for executives and security teams
Plain-English summary
This vulnerability affects manageability firmware in some Intel Ethernet adapters and Intel I225 controllers. An attacker would already need privileged local access, but successful abuse could let them change control flow and gain higher impact over system integrity or availability. The business risk is mainly on systems using affected Intel network hardware with exposed or shared administrator access.
Executive priority
Prioritize validation for servers, workstations, and appliances where Intel Ethernet manageability firmware is present and privileged local access is shared or broadly delegated. This is not shown as internet-exploitable, but the integrity and availability impacts justify timely firmware review.
Technical view
CVE-2021-33157 is a CWE-691 insufficient control flow management flaw in some Intel Ethernet Adapters and Intel Ethernet Controller I225 Manageability firmware. CVSS 3.1 is 7.2, with local access, high attack complexity, high privileges required, no user interaction, changed scope, and high integrity and availability impact.
Likely exposure
Exposure is limited to systems with the affected Intel Ethernet adapter or I225 manageability firmware versions. The bundle does not enumerate versions, so validation must rely on Intel SA-00756 and OEM firmware information.
Exploitation context
The supplied data does not show CISA KEV listing or cited evidence of active exploitation. Exploitation requires local access and high privileges, which reduces broad remote risk but matters on shared, managed, or already-compromised systems.
Researcher notes
The source bundle gives CVE metadata, CVSS, CWE-691, and the Intel advisory reference, but not specific affected versions or patch details. Do not assert active exploitation. Treat exposure and remediation as dependent on Intel SA-00756 and relevant OEM firmware advisories.
Mitigation direction
- Review Intel SA-00756 for affected firmware versions and vendor remediation guidance.
- Inventory systems using Intel Ethernet adapters or Intel I225 manageability firmware.
- Apply Intel or OEM firmware updates only when confirmed by vendor guidance.
- Limit local administrator access on systems with potentially affected hardware.
- Track exceptions where firmware status cannot be confirmed.
Validation and detection
- Compare adapter model and manageability firmware version against Intel SA-00756.
- Confirm whether each system uses affected Intel Ethernet hardware.
- Review privileged local account exposure on potentially affected systems.
- Verify remediation state through approved asset or firmware inventory records.
- Monitor CVE and Intel advisory updates for changed affected-version details.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-691: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-33157 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:H0.85.8Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.2HighVector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:H
Source materials
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Insufficient Control Flow Management
Insufficient Control Flow Management represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.