Security readout for executives and security teams
Plain-English summary
CVE-2019-11707 is a Mozilla browser and mail-client flaw that was abused in targeted attacks. A user running an affected Firefox, Firefox ESR, or Thunderbird version could be exposed through malicious web or message content. The business concern is endpoint compromise risk on legacy installations, not a broad server-side exposure.
Executive priority
Treat this as a high-priority legacy endpoint cleanup item. Because exploitation is confirmed, vulnerable installations should be patched or removed quickly, especially on systems used by high-risk staff or exposed to untrusted web and email content.
Technical view
The flaw is a CWE-843 type confusion issue in JavaScript object manipulation involving Array.pop. Mozilla states it can cause an exploitable crash and affects Firefox before 67.0.3, Firefox ESR before 60.7.1, and Thunderbird before 60.7.2. The CVSS 3.1 score is 8.8 with network attack vector and user interaction required.
Likely exposure
Exposure is most likely on unmanaged or legacy endpoints still running vulnerable Firefox, Firefox ESR, or Thunderbird versions. Current supported Mozilla releases should not be assumed affected from the provided sources.
Exploitation context
Mozilla reported targeted attacks in the wild, and CISA lists CVE-2019-11707 in the Known Exploited Vulnerabilities catalog. The provided sources do not include exploit mechanics, campaign details, or indicators of compromise.
Researcher notes
The public bundle supports affected products, fixed version thresholds, CVSS, CWE, and active exploitation status. It does not provide technical exploit details, reliable detection indicators, or evidence of affected products beyond Firefox, Firefox ESR, and Thunderbird.
Mitigation direction
- Upgrade Firefox to 67.0.3 or later.
- Upgrade Firefox ESR to 60.7.1 or later.
- Upgrade Thunderbird to 60.7.2 or later.
- Remove or isolate unsupported legacy Mozilla installations.
- Check Mozilla and OS vendor guidance for distribution-specific packages.
Validation and detection
- Inventory Firefox, Firefox ESR, and Thunderbird versions across endpoints.
- Confirm no installation remains below the fixed versions.
- Review vulnerability scanner results for CVE-2019-11707 coverage.
- Prioritize systems used for web browsing or email handling.
- Check patch management records for Mozilla updates from June 2019 onward.
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.
CWE-843: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2019-11707 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
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.mozilla.org/security/advisories/mfsa2019-20/CVE reference · x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2019-18/CVE reference · x_refsource_MISC
- https://bugzilla.mozilla.org/show_bug.cgi?id=1544386CVE reference · x_refsource_MISC
- GLSA-201908-12CVE reference · vendor-advisory, x_refsource_GENTOO
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-11707CVE reference · government-resource
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.
Access of Resource Using Incompatible Type ('Type Confusion')
Access of Resource Using Incompatible Type ('Type Confusion') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.