Security readout for executives and security teams
Plain-English summary
CVE-2024-4367 is a PDF.js font-handling flaw that can let a malicious PDF run JavaScript inside the PDF.js viewer context. Mozilla fixed affected Firefox, Firefox ESR, and Thunderbird versions. Organizations that view untrusted PDFs in browsers, mail clients, or embedded PDF.js viewers should treat this as a timely patching issue.
Executive priority
Prioritize patching in environments where PDFs are routinely received from outside the organization. The business risk is code execution inside a document viewer context, with public technical writeups available, but no KEV-backed active exploitation signal in the supplied evidence.
Technical view
The issue is a missing type check while handling fonts in PDF.js, classified as CWE-754. The CVE lists arbitrary JavaScript execution in the PDF.js context and affects Firefox before 126, Firefox ESR before 115.11, and Thunderbird before 115.11. Mozilla advisories and the PDF.js 4.2.67 release are the primary remediation references.
Likely exposure
Exposure is most likely where users open PDFs from email, web downloads, portals, or document-management systems using affected Mozilla products or embedded PDF.js components. The bundle also includes downstream ecosystem references, indicating deployments beyond desktop browsers may matter.
Exploitation context
CISA KEV status is false in the supplied bundle, so confirmed active exploitation is not established here. Public research and exploit-reference links exist, which raises validation urgency, but this assessment does not rely on or provide exploit mechanics.
Researcher notes
The core evidence supports a missing type check in PDF.js font handling. Researchers should focus on version confirmation, embedded-library usage, and downstream products that include PDF.js. Do not assume every PDF viewer is affected without matching its component lineage and version.
Mitigation direction
- Update Firefox to 126 or later where applicable.
- Update Firefox ESR to 115.11 or later.
- Update Thunderbird to 115.11 or later.
- Update embedded PDF.js deployments using Mozilla release guidance.
- Check Debian and vendor advisories for packaged application updates.
- Restrict untrusted PDF handling until affected viewers are patched.
Validation and detection
- Inventory Firefox, Firefox ESR, Thunderbird, and bundled PDF.js versions.
- Identify applications that render user-supplied PDFs in-browser.
- Confirm PDF.js package versions against the 4.2.67 release reference.
- Review vendor advisories for downstream product-specific exposure.
- Check whether PDF workflows process external or customer-submitted files.
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-754: 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-2024-4367 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
- Medium
- CVSS
- 5.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
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.
SSVC decision data
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:H/PR:N/UI:N/S:U/C:L/I:L/A:L2.23.4CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
5.6MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://bugzilla.mozilla.org/show_bug.cgi?id=1893645CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2024-21/CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2024-22/CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2024-23/CVE reference, mozilla
- https://lists.debian.org/debian-lts-announce/2024/05/msg00010.htmlCVE reference, mozilla
- https://lists.debian.org/debian-lts-announce/2024/05/msg00012.htmlCVE reference, mozilla
- https://github.com/mozilla/pdf.js/releases/tag/v4.2.67CVE reference, CVE
- https://codeanlabs.com/blog/research/cve-2024-4367-arbitrary-js-execution-in-pdf-js/CVE reference, CVE
- https://github.com/gogs/gogs/issues/7928CVE reference, CVE
- https://www.exploit-db.com/exploits/52273CVE reference, CVE
- https://cert-portal.siemens.com/productcert/html/ssa-827383.htmlCVE reference, siemens-SADP
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.
Improper Check for Unusual or Exceptional Conditions
Improper Check for Unusual or Exceptional Conditions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.