Security readout for executives and security teams
Plain-English summary
CVE-2021-34975 is a high-severity Foxit PDF Reader flaw that can let an attacker run code when a user opens a malicious PDF or visits a malicious page. The known affected version in the source bundle is 11.0.1.49938. No provided source confirms active exploitation.
Executive priority
Treat this as a high-priority endpoint patching issue where Foxit PDF Reader is deployed. Business urgency is highest for staff frequently handling external documents, because compromise requires user interaction but can lead to full code execution in the user process.
Technical view
The flaw is a CWE-416 use-after-free in Foxit PDF Reader's transitionToState method. It stems from failing to validate an object's existence before operating on it. Successful exploitation can execute code in the current process context, with user interaction required. CVSS is 7.8 high.
Likely exposure
Exposure is most likely on endpoints using Foxit PDF Reader 11.0.1.49938, especially where users open external PDFs or browse untrusted content. The source bundle does not establish other affected versions or platforms.
Exploitation context
The sources describe remote attacker code execution, but exploitation requires the target to open a malicious file or visit a malicious page. The CVE is not marked KEV in the bundle, so active exploitation should not be assumed from these sources alone.
Researcher notes
Evidence is limited to the CVE record, ZDI advisory, and Foxit bulletin reference. The affected version listed is 11.0.1.49938. The bundle does not provide exploit availability, fixed version details, or confirmed in-the-wild activity.
Mitigation direction
- Inventory Foxit PDF Reader installations and identify version 11.0.1.49938.
- Check Foxit security bulletins for fixed versions and vendor upgrade guidance.
- Prioritize updates on systems handling external PDFs or high-risk email attachments.
- Reduce exposure to untrusted PDFs until vendor guidance is applied.
- Use standard endpoint controls to contain document-based code execution risk.
Validation and detection
- Confirm installed Foxit PDF Reader versions across managed endpoints.
- Compare installed builds against Foxit's security bulletin guidance.
- Check whether Foxit Reader is the default PDF handler on exposed workstations.
- Review document-ingress workflows for external PDFs and web downloads.
- Do not mark active exploitation without KEV or cited source evidence.
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-416: 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-34975 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
- 7.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/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.
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:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.8HighVector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- ZDI-21-1206CVE reference · x_research-advisory
- vendor-provided URLCVE reference · vendor-advisory
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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.