LiveActive security incident?Get immediate response
CVE Record

CVE-2021-45952: Dnsmasq 2.86 has a heap-based buffer overflow in dhcp_reply (called from dhcp_packet and FuzzDhcp).

Dnsmasq 2.86 has a heap-based buffer overflow in dhcp_reply (called from dhcp_packet and FuzzDhcp). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities, to the best of our knowledge.

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 reported heap buffer overflow in dnsmasq 2.86’s DHCP reply handling. The record also notes the vendor’s position that this CVE group does not represent real vulnerabilities. There is no CVSS score, no KEV listing, and no cited evidence of exploitation.

Executive priority

Track this as a low-certainty vulnerability management item, not an emergency. Prioritize confirming whether dnsmasq 2.86 with DHCP is present, then follow vendor or distribution guidance if they classify it as actionable.

Technical view

The report ties the issue to dhcp_reply, reached from dhcp_packet and FuzzDhcp, apparently from fuzzing. The available CVE data lacks CWE, affected CPEs, impact scoring, and confirmed exploitability. Vendor discussion disputes that CVE-2021-45951 through CVE-2021-45957 are real vulnerabilities.

Likely exposure

Potential exposure is limited to environments running dnsmasq 2.86 with DHCP handling enabled, but the source bundle does not provide confirmed affected product scope. Treat exposure as inventory-driven until vendor or distribution guidance clarifies practical impact.

Exploitation context

The source bundle does not show active exploitation, and the CVE is not listed as KEV. Evidence appears tied to fuzzing rather than public attack activity. The vendor disputes real-world vulnerability status for this CVE group.

Researcher notes

Key uncertainty is exploitability. The CVE description reports a heap overflow, while vendor discussion says this CVE group does not represent real vulnerabilities. No CVSS, CWE, CPE, patch, or exploitation evidence is included in the provided bundle.

Mitigation direction

  • Check dnsmasq vendor and distribution advisories for authoritative status.
  • Update dnsmasq if your vendor provides a supported security or stability release.
  • Restrict DHCP services to trusted network segments only.
  • Disable dnsmasq DHCP functionality where it is not operationally required.
  • Monitor for revised CVE, OSV, or vendor guidance.

Validation and detection

  • Inventory systems running dnsmasq and record exact package versions.
  • Confirm whether dnsmasq DHCP handling is enabled on each asset.
  • Review vendor or distribution advisories for CVE-2021-45952 references.
  • Check whether DHCP traffic is reachable only from intended local networks.
  • Review crash logs for dnsmasq instability around DHCP processing.
Prepared
Confidence
medium
Sources
6

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-2021-45952 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
0Timeline events
0ADP providers
5Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

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.