Security readout for executives and security teams
Plain-English summary
This issue can crash or disrupt a D-Link DSL-2740R router by hitting vulnerable HNAP handling. The listed device line is end of life, and the CVE notes D-Link will not patch it. Business urgency depends on whether these routers still exist in your environment and whether their management interface is reachable.
Executive priority
Treat this as a legacy infrastructure retirement issue. It is not documented here as actively exploited or code execution, but the affected device is unsupported and unpatched, so continued use carries avoidable operational risk.
Technical view
CVE-2021-29294 is a null pointer dereference in D-Link DSL-2740R UK_1.01, involving send_hnap_unauthorized. The source describes denial of service from a crafted POST request to /HNAP1/. No CVSS, CWE, or vendor fix is provided in the bundle; all hardware revisions are stated to be end of life.
Likely exposure
Exposure is most likely where D-Link DSL-2740R routers remain deployed, especially if management or HNAP functionality is reachable from untrusted networks. The source bundle does not identify other products or versions beyond DSL-2740R UK_1.01.
Exploitation context
The source says a remote malicious user could cause denial of service, but it does not cite active exploitation. The CVE is not marked in CISA KEV in the provided bundle. Public evidence here supports DoS risk, not compromise, persistence, or data theft.
Researcher notes
Evidence is limited to the CVE description and D-Link references. The affected array in the bundle is not populated, while the description names DSL-2740R UK_1.01 and says all hardware revisions are end of life. No safe fix is identified beyond replacement or access restriction.
Mitigation direction
- Inventory and replace D-Link DSL-2740R devices because the product is end of life.
- Restrict router management access to trusted administrative networks only.
- Block untrusted access to HNAP or administrative paths where feasible.
- Check D-Link advisories for any deployment-specific guidance.
- Monitor for availability issues affecting legacy router segments.
Validation and detection
- Confirm whether any DSL-2740R devices remain in production or lab networks.
- Record firmware version and hardware revision for each identified device.
- Check whether management interfaces are exposed to the internet or user networks.
- Review logs for unexpected requests to /HNAP1/.
- Document replacement or isolation status for each affected router.
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-2021-29294 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.dlink.com/en/security-bulletin/CVE reference · x_refsource_MISC
- https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10213CVE 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.