Security readout for executives and security teams
Plain-English summary
This is a Mozilla browser and mail-client security flaw where normal subdomain boundaries could be bypassed in some document.domain scenarios. A compromised or hostile subdomain could potentially run script against pages on another related subdomain. The main business risk is from unpatched legacy Firefox, Firefox ESR, or Thunderbird installations.
Executive priority
Treat this as a legacy-client cleanup priority. It is not reported as actively exploited in the provided sources, but it can undermine browser trust boundaries for organizations with old Mozilla clients and related subdomain applications.
Technical view
CVE-2019-11711 concerns inner window reuse failing to account for document.domain-based origin relaxation. Where pages on different subdomains used document.domain cooperatively, one page could inject script into arbitrary pages on the other subdomain. Mozilla lists Firefox ESR before 60.8, Firefox before 68, and Thunderbird before 60.8 as affected.
Likely exposure
Exposure is most likely on legacy managed endpoints, long-lived ESR deployments, older Linux desktop packages, or environments still running Thunderbird before 60.8. Risk increases for organizations with related subdomains that historically used document.domain.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. Exploitation depends on a specific cross-subdomain document.domain condition and an affected Mozilla client, so this is not a universal server-side exposure.
Researcher notes
Focus validation on client version exposure and document.domain-dependent subdomain trust assumptions. The public description is concise and does not include CVSS, CWE, exploit details, or operational indicators in the provided bundle.
Mitigation direction
- Update Firefox to version 68 or later.
- Update Firefox ESR to version 60.8 or later.
- Update Thunderbird to version 60.8 or later.
- Apply relevant Debian, openSUSE, Gentoo, or vendor security packages.
- Review legacy document.domain use across related subdomains.
Validation and detection
- Inventory managed endpoints for affected Firefox, Firefox ESR, and Thunderbird versions.
- Confirm no Firefox ESR below 60.8 remains in supported images.
- Confirm no Firefox below 68 remains in managed browser fleets.
- Confirm no Thunderbird below 60.8 remains on user systems.
- Identify applications relying on document.domain across subdomains.
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.
CVE-2019-11711 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.mozilla.org/security/advisories/mfsa2019-21/CVE reference · x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2019-22/CVE reference · x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2019-23/CVE reference · x_refsource_MISC
- https://bugzilla.mozilla.org/show_bug.cgi?id=1552541CVE reference · x_refsource_MISC
- [debian-lts-announce] 20190802 [SECURITY] [DLA 1869-1] firefox-esr security updateCVE reference · mailing-list, x_refsource_MLIST
- [debian-lts-announce] 20190802 [SECURITY] [DLA 1870-1] thunderbird security updateCVE reference · mailing-list, x_refsource_MLIST
- GLSA-201908-12CVE reference · vendor-advisory, x_refsource_GENTOO
- GLSA-201908-20CVE reference · vendor-advisory, x_refsource_GENTOO
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.