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CVE Record

CVE-2009-4630: Mozilla Necko, as used in Firefox, SeaMonkey, and other applications, performs DNS prefetching of domain na...

Mozilla Necko, as used in Firefox, SeaMonkey, and other applications, performs DNS prefetching of domain names contained in links within local HTML documents, which makes it easier for remote attackers to determine the network location of the application's user by logging DNS requests. NOTE: the vendor disputes the significance of this issue, stating "I don't think we necessarily need to worry about that case."

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

This CVE describes a privacy leak, not a direct system compromise. Mozilla Necko could prefetch DNS names from links in local HTML files, allowing an observer of DNS requests to infer a user’s network location. Mozilla disputed the practical significance, and the source bundle provides no severity score.

Executive priority

Low priority unless the organization has users whose network location privacy is sensitive. There is no sourced evidence of exploitation or business-disruptive impact, and the vendor disputed the significance. Handle through browser hardening and privacy review rather than emergency response.

Technical view

Mozilla Necko, used by Firefox, SeaMonkey, and other applications, performed DNS prefetching for domain names found in links inside local HTML documents. The reported impact is information disclosure through DNS logs. The CVE record does not provide affected versions, CVSS, CWE, patch details, or confirmed exploit activity.

Likely exposure

Potential exposure is limited to Mozilla Necko-based applications, specifically Firefox, SeaMonkey, and unnamed other applications. The bundle does not identify affected versions or platforms. Risk is most relevant where local HTML content is opened and DNS queries can be observed or logged by another party.

Exploitation context

The bundle does not cite active exploitation, public exploit use, or KEV listing. The described scenario depends on DNS prefetch behavior and visibility into DNS requests. Treat this as a privacy and tracking concern rather than evidence of remote code execution or account compromise.

Researcher notes

Evidence is sparse. The CVE is based on Mozilla Bugzilla references and notes vendor disagreement. No affected version range, CVSS vector, CWE, patch, or mitigation is included in the bundle. Avoid overstating impact beyond DNS-request-based location inference.

Mitigation direction

  • Check current Mozilla guidance and bug history for DNS prefetch behavior and supported controls.
  • Keep Firefox, SeaMonkey, and other Necko-based applications on vendor-supported versions.
  • Review enterprise browser policies for privacy controls related to DNS resolution and prefetching.
  • Avoid relying on local HTML documents to conceal user network location.

Validation and detection

  • Inventory Firefox, SeaMonkey, and other applications using Mozilla Necko in the environment.
  • Confirm whether deployed versions perform DNS prefetching for links in local HTML documents.
  • Review DNS logging exposure for sensitive users or environments.
  • Document whether vendor-supported browser policy controls address DNS prefetch privacy risk.
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

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CVE-2009-4630 mapping review

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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
3Source 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

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