Security readout for executives and security teams
Plain-English summary
CVE-2021-34829 is a high-severity flaw in D-Link DAP-1330 firmware 1.13B01 BETA. A nearby network attacker could exploit a buffer overflow without authentication and run code on the device. Treat exposed or still-deployed affected devices as urgent network infrastructure risk.
Executive priority
Prioritize remediation if affected devices remain in use. The issue is unauthenticated code execution on network equipment, but the evidence provided limits scope to one beta firmware version and does not confirm active exploitation.
Technical view
The flaw is in handling the HNAP_AUTH HTTP header. User-supplied data is copied into a fixed-length buffer without adequate length validation, matching CWE-120. The CVSS vector is AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, meaning network-adjacent, low complexity, unauthenticated code execution with high impact.
Likely exposure
Exposure appears limited to D-Link DAP-1330 devices running 1.13B01 BETA firmware, especially where management or HNAP-related HTTP handling is reachable from adjacent networks. The source bundle does not identify other affected products or versions.
Exploitation context
The sources describe unauthenticated, network-adjacent arbitrary code execution. The CVE is not listed as KEV in the provided bundle, and no cited source here confirms active exploitation.
Researcher notes
Analysis should stay scoped to DAP-1330 1.13B01 BETA unless additional vendor evidence expands impact. The public description attributes the bug to improper HNAP_AUTH header length validation before fixed-buffer copy. No patch details are present in the provided source bundle.
Mitigation direction
- Inventory D-Link DAP-1330 devices and identify firmware versions.
- Check D-Link and ZDI guidance for vendor-supported remediation.
- Remove 1.13B01 BETA firmware from production where possible.
- Restrict device management HTTP access to trusted admin networks.
- Segment affected devices away from untrusted adjacent networks.
Validation and detection
- Confirm whether any DAP-1330 runs firmware 1.13B01 BETA.
- Map which networks can reach the device HTTP management surface.
- Review logs for unexpected management access from adjacent networks.
- Verify remediation against current vendor guidance before closure.
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-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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-34829 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 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/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:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.8HighVector: CVSS:3.0/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://www.zerodayinitiative.com/advisories/ZDI-21-681/CVE reference · x_refsource_MISC
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.
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.