Security readout for executives and security teams
Plain-English summary
CVE-2021-46753 is a critical AMD Secure Processor issue involving insufficient validation of sensor fusion hub header length fields. A malicious Uapp or ABL could allow mapping of that region and overwriting internal data structures, potentially exposing sensitive information and altering trusted processor state.
Executive priority
Treat this as a high-priority firmware risk for affected AMD platforms, especially regulated or sensitive systems. Business urgency is driven by critical severity and confidentiality/integrity impact, but remediation planning depends on AMD and OEM guidance because fixed versions are not included in the provided source data.
Technical view
The flaw is in AMD ASP sensor fusion hub header parsing. Missing length-field validation may let an attacker using a malicious Uapp or ABL map the ASP sensor fusion hub region and overwrite data structures. Reported impact is high confidentiality and integrity loss, with no availability impact stated.
Likely exposure
Exposure appears limited to listed AMD Ryzen and Athlon platforms using affected AGESA-related firmware. The source lists multiple desktop and mobile processor families but only says versions are various, so organizations must confirm exact platform and firmware applicability with AMD or OEM guidance.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. The description requires a malicious Uapp or ABL, which suggests specialized preconditions, but the CVSS vector reports network, low-complexity, no-privilege, no-user-interaction characteristics.
Researcher notes
The key uncertainty is exploitability context: the CVSS vector is severe, while the description references a malicious Uapp or ABL. Do not assume broad remote exploitation without additional evidence. Focus research on affected AGESA firmware lineage, ASP sensor fusion hub handling, and vendor-confirmed update paths.
Mitigation direction
- Review AMD-SB-4001 for product-specific guidance and affected AGESA details.
- Check system OEM advisories for applicable BIOS or firmware updates.
- Prioritize platforms matching the listed Ryzen and Athlon processor families.
- Restrict untrusted firmware, boot components, and platform management code paths where possible.
- Track vendor updates until exact fixed firmware applicability is confirmed.
Validation and detection
- Inventory endpoints and servers for the listed AMD processor families.
- Record BIOS, firmware, and AGESA-related version data from each platform.
- Compare inventory against AMD-SB-4001 and OEM advisories.
- Confirm whether compensating controls limit unauthorized firmware or boot component changes.
- Document systems where vendor guidance remains unavailable or ambiguous.
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.
CVE-2021-46753 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
- Critical
- CVSS
- 9.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N3.95.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-4001CVE reference · vendor-advisory
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.