Security readout for executives and security teams
Plain-English summary
CVE-2021-38111 is a high-severity buffer overflow in the DEF CON 27 badge. A nearby attacker could send an oversized NFMI packet and potentially compromise confidentiality, integrity, and availability. This appears to be niche event hardware, not a broad enterprise software issue.
Executive priority
Prioritize this as a targeted hardware exposure, not an enterprise-wide emergency. Address it promptly where DEF CON 27 badges are used, connected, or demonstrated around untrusted people, because the stated impact is full compromise of the device.
Technical view
The CVE describes CWE-120 in the DEF CON 27 badge, reachable over NFMI, with CVSS 3.1 score 8.8 and adjacent-network attack vector. The source bundle does not name a patch, affected firmware versions, CPEs, or vendor remediation.
Likely exposure
Exposure is likely limited to DEF CON 27 badges, especially powered devices using or listening on NFMI in close physical proximity. The affected metadata lists vendor, product, and versions as n/a, so asset identification requires local inventory.
Exploitation context
The CVE states remote exploitation over NFMI using an oversized packet, but KEV status is false and the provided sources do not establish active exploitation in the wild. Public research references exist, increasing reproducibility risk for researchers with the hardware.
Researcher notes
Key gaps remain: affected versions are not enumerated, no CPE is provided, and no patch is named. Analysis should stay tied to the DEF CON 27 badge, NFMI attack surface, CWE-120 classification, and CVSS adjacent-vector scoring.
Mitigation direction
- Inventory any DEF CON 27 badges and determine whether they are powered or operational.
- Avoid using NFMI features in untrusted close-range environments until guidance is confirmed.
- Check DEF CON and project repository sources for firmware or handling recommendations.
- If supported, disable NFMI functionality when it is not required.
- Treat affected badges as untrusted devices on connected systems.
Validation and detection
- Confirm whether DEF CON 27 badges exist in labs, demos, collections, or connected environments.
- Review device configuration to determine whether NFMI functionality is active.
- Check the referenced DEF CON talk and SDR repository for defensive context only.
- Look for vendor or community remediation notes before applying changes.
- Document any compensating controls if no patch is available.
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-120: 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-2021-38111 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
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/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:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://defcon.org/html/defcon-29/dc-29-speakers.html#kintighCVE reference
- https://github.com/skintigh/defcon27_badge_sdrCVE 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.