Security readout for executives and security teams
Plain-English summary
This flaw could let already-privileged local software on affected AMD 3rd Gen EPYC systems read sensitive memory through insufficiently validated ASP BIOS and DRTM commands. It is not a remote break-in issue, but it matters on servers that process high-value secrets or run untrusted workloads.
Executive priority
Treat this as a targeted firmware hygiene issue, not an emergency internet-facing incident. Prioritize high-value EPYC servers and environments where local privileged compromise could expose sensitive memory.
Technical view
CVE-2021-26343 is an information disclosure issue in AGESA affecting AMD 3rd Gen EPYC, tied to insufficient validation of ASP BIOS and DRTM commands. CVSS 3.1 is 5.5: local attack vector, low complexity, low privileges, no user interaction, high confidentiality impact only.
Likely exposure
Exposure is likely limited to AMD 3rd Gen EPYC platforms running affected AGESA/BIOS versions. The source bundle lists versions only as “various,” so exact exposure requires checking AMD and OEM firmware guidance for each server model.
Exploitation context
The supplied sources do not show CISA KEV listing, active exploitation, or public weaponization. The vulnerability requires local privileged or supervisor-level x86 software, so risk rises after endpoint or host compromise rather than from the internet directly.
Researcher notes
Key evidence gaps are exact vulnerable AGESA builds, OEM-specific fixed BIOS versions, and any practical exploitation details. Avoid assuming broader AMD product impact beyond the supplied affected product statement.
Mitigation direction
- Review AMD-SB-1032 and OEM advisories for affected AGESA or BIOS versions.
- Update affected 3rd Gen EPYC server BIOS or firmware using vendor-approved packages.
- Prioritize systems handling credentials, encryption keys, regulated data, or multi-tenant workloads.
- Restrict local administrative access and untrusted kernel-level drivers on EPYC hosts.
- Track vendor guidance if exact firmware applicability is unclear.
Validation and detection
- Inventory AMD 3rd Gen EPYC systems and record current BIOS and AGESA versions.
- Compare firmware versions against AMD-SB-1032 and server OEM security advisories.
- Confirm firmware updates were successfully applied and remain supported by the OEM.
- Review privileged software, drivers, and hypervisor components allowed on affected hosts.
- Check vulnerability management data for CVE-2021-26343 coverage and exceptions.
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
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CWE-668: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-26343 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
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N1.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-1032CVE 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.
Exposure of Resource to Wrong Sphere
Exposure of Resource to Wrong Sphere represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.