Security readout for executives and security teams
Plain-English summary
This is a low-severity AMD firmware issue. A highly privileged attacker who can access the BIOS menu or UEFI shell could tamper with SPI ROM structure headers, potentially causing memory corruption or denial of service. The sources do not indicate remote exploitation or active exploitation.
Executive priority
Treat as routine firmware risk management, not an emergency. The vulnerability has meaningful impact only after high-privilege local firmware-level access, but affected server and workstation fleets should still be checked during normal BIOS and platform firmware maintenance.
Technical view
CVE-2021-46772 is insufficient input validation in the ABL affecting listed AMD EPYC, Ryzen, Athlon, and Threadripper platforms. Malformed SPI ROM structure headers can trigger out-of-bounds read and write conditions, mapped to CWE-125 and CWE-787. CVSS 3.1 is 3.9 with local, high-complexity, high-privilege requirements.
Likely exposure
Exposure is most relevant for systems using the affected AMD processor families and platform firmware versions listed by AMD. Practical exposure depends on firmware lineage, OEM BIOS packages, and whether attackers can reach BIOS setup or a UEFI shell with high privilege.
Exploitation context
The source bundle marks CISA KEV as false. The stated attack path is local and privileged, requiring BIOS menu or UEFI shell access. No cited source in the bundle reports active exploitation, public exploit use, or a remote attack vector.
Researcher notes
The key research question is whether a platform exposes the vulnerable ABL path and SPI ROM header parsing behavior. The bundle does not provide proof-of-concept details, fixed version mappings for every product, or evidence of exploitation. Avoid assuming all AMD systems are affected.
Mitigation direction
- Review AMD advisories SB-3003, SB-4004, and SB-5002 for platform-specific guidance.
- Check OEM BIOS or firmware updates for affected AMD platforms.
- Restrict BIOS setup access with administrative controls and physical security.
- Disable or restrict UEFI shell access where operationally feasible.
- Prioritize systems where untrusted administrators or physical access are realistic.
Validation and detection
- Inventory AMD EPYC, Ryzen, Athlon, and Threadripper systems against AMD affected product lists.
- Record BIOS, UEFI, AGESA, or PI firmware versions from asset management sources.
- Compare installed firmware to AMD and OEM advisory guidance.
- Confirm BIOS setup and UEFI shell access are restricted to trusted administrators.
- Track this CVE separately from KEV-driven emergency patch queues.
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-125: 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 lookupCWE-787: 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-2021-46772 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
- Low
- CVSS
- 3.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:L/A:L
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:L/A:L0.82.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
3.9LowVector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://www.amd.com/en/resources/product-security/bulletin/amd-sb-3003.htmlCVE reference · vendor-advisory
- https://www.amd.com/en/resources/product-security/bulletin/amd-sb-4004.htmlCVE reference
- https://www.amd.com/en/resources/product-security/bulletin/amd-sb-5002.htmlCVE reference
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.
Out-of-bounds Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.