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CVE Record

CVE-2019-9818: A race condition is present in the crash generation server used to generate data for the crash reporter.

A race condition is present in the crash generation server used to generate data for the crash reporter. This issue can lead to a use-after-free in the main process, resulting in a potentially exploitable crash and a sandbox escape. *Note: this vulnerability only affects Windows. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 60.7, Firefox < 67, and Firefox ESR < 60.7.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2019-9818 is a Windows-only Mozilla vulnerability in crash reporter data generation. On affected Firefox, Firefox ESR, and Thunderbird versions, a race condition could cause memory to be used after it was freed, creating a potentially exploitable crash and possible sandbox escape.

Executive priority

Prioritize remediation where legacy Mozilla clients remain on Windows, especially on systems handling email or web browsing. The business risk is sandbox escape potential, but urgency is lower for fully updated fleets and non-Windows environments.

Technical view

The issue is a race condition in Mozilla’s crash generation server used by the crash reporter. Mozilla describes the outcome as a use-after-free in the main process, with potential sandbox escape impact. It affects Thunderbird before 60.7, Firefox before 67, and Firefox ESR before 60.7 on Windows only.

Likely exposure

Exposure is limited to Windows systems running Firefox below 67, Firefox ESR below 60.7, or Thunderbird below 60.7. Other operating systems are stated as unaffected. Current exposure is most likely in unmanaged, legacy, or embedded desktop environments.

Exploitation context

The provided sources describe a potentially exploitable crash and sandbox escape, but do not state active exploitation. The CVE is not listed as KEV in the supplied bundle. Treat exploitation status as unconfirmed unless newer vendor or CISA evidence is found.

Researcher notes

Key constraints are Windows-only impact and affected-version boundaries from Mozilla. The bundle lacks CVSS, CWE, exploit telemetry, and detailed Bugzilla content. Do not infer active exploitation or broader platform impact from the sandbox escape wording alone.

Mitigation direction

  • Upgrade Firefox to 67 or later on Windows systems.
  • Upgrade Firefox ESR to 60.7 or later where ESR is used.
  • Upgrade Thunderbird to 60.7 or later on Windows systems.
  • Remove unsupported legacy Mozilla installations from managed endpoints.
  • Review Mozilla advisories for any environment-specific guidance.

Validation and detection

  • Inventory Windows endpoints for Firefox, Firefox ESR, and Thunderbird versions.
  • Confirm no affected Mozilla versions remain below the fixed releases.
  • Check vulnerability scanner findings mapped to CVE-2019-9818.
  • Validate software deployment records show completed upgrades.
  • Confirm non-Windows findings are not false positives against this CVE.
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.

description · low confidence lookup

Privilege behavior lookup

The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2019-9818 mapping review

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

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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
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
MozillaThunderbirdunspecifiedListed
MozillaFirefoxunspecifiedListed
MozillaFirefox ESRunspecifiedListed
Weakness

CWE details

No CWE listed

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