LiveActive security incident?Get immediate response
CVE Record

CVE-2021-34201: D-Link DIR-2640-US 1.01B04 is vulnerable to Buffer Overflow.

D-Link DIR-2640-US 1.01B04 is vulnerable to Buffer Overflow. There are multiple out-of-bounds vulnerabilities in some processes of D-Link AC2600(DIR-2640). Local ordinary users can overwrite the global variables in the .bss section, causing the process crashes or changes.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This CVE describes a memory corruption issue in D-Link DIR-2640-US firmware 1.01B04. A local ordinary user may be able to crash affected processes or alter behavior by overwriting memory. The provided sources do not establish remote exploitability, active exploitation, CVSS severity, or a confirmed fixed firmware version.

Executive priority

Treat this as a targeted asset-management issue, not a confirmed emergency. Prioritize identifying affected routers and checking vendor support status. Escalate if affected devices are shared, unmanaged, or accessible by untrusted local users.

Technical view

The record describes multiple out-of-bounds vulnerabilities in D-Link AC2600 DIR-2640 processes. Local ordinary users can overwrite global variables in the .bss section, causing process crashes or changes. Affected evidence is limited to DIR-2640-US firmware 1.01B04; structured CPE, CWE, CVSS, and vendor fix details are not supplied.

Likely exposure

Exposure appears limited to D-Link DIR-2640-US devices running firmware 1.01B04 where local ordinary users can reach the vulnerable processes. The source bundle does not support broader model, version, or remote exposure claims.

Exploitation context

The CVE is not listed as KEV in the provided bundle. Sources describe local user impact only. No provided source confirms exploitation in the wild, public weaponization, or remote attack paths.

Researcher notes

Evidence is sparse. The GitHub reference appears to be the primary technical source, while the CVE record lacks CVSS, CWE, CPE, and fixed-version details. Avoid expanding scope beyond DIR-2640-US 1.01B04 without additional vendor confirmation.

Mitigation direction

  • Inventory DIR-2640-US devices and confirm firmware versions.
  • Check D-Link security bulletins and support pages for vendor guidance.
  • Upgrade firmware only to versions confirmed by D-Link as appropriate.
  • Restrict local device access to trusted administrators and networks.
  • Retire or replace devices if no supported fix is available.

Validation and detection

  • Confirm whether any DIR-2640-US device runs firmware 1.01B04.
  • Review D-Link advisories for this model and CVE reference.
  • Verify untrusted users cannot access local management or shell functions.
  • Check asset records for unsupported or end-of-life D-Link routers.
  • Document compensating controls where firmware remediation is unavailable.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · low confidence lookup

CVE-2021-34201 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
3Timeline events
1ADP providers
3Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.