Security readout for executives and security teams
Plain-English summary
This is a low-severity Foxit PDF Reader issue that can leak sensitive information when a user opens a malicious PDF or visits a malicious page. It is mainly a workstation risk, not a server exposure, and the provided sources do not show active exploitation.
Executive priority
Treat as routine patch hygiene unless Foxit Reader is widely deployed or used with untrusted PDFs. It does not warrant emergency response based on the provided evidence, but affected endpoints should be remediated through normal vulnerability management.
Technical view
CVE-2021-34976 is a CWE-416 use-after-free in Foxit PDF Reader PDF parsing. The flaw is missing validation that an object exists before operations on it. The source lists Foxit PDF Reader 11.0.1.49938. CVSS 3.0 is 3.3 with local attack vector, user interaction required, and low confidentiality impact.
Likely exposure
Likely exposure is limited to endpoints running Foxit PDF Reader 11.0.1.49938, especially users who open PDFs from email, browsers, downloads, or other untrusted sources. The source bundle does not confirm other affected versions or CPE coverage.
Exploitation context
User interaction is required: the target must open a malicious file or visit a malicious page. The ZDI description says the issue may be combined with other vulnerabilities for code execution. KEV is false, and the provided sources do not report active exploitation.
Researcher notes
The source evidence is narrow: one affected version is listed and vendor guidance is referenced but not summarized in the bundle. Do not assume broader affected versions, fixed builds, exploit availability, or active exploitation without consulting the Foxit advisory directly.
Mitigation direction
- Inventory endpoints for Foxit PDF Reader 11.0.1.49938.
- Check Foxit security bulletins for fixed versions and vendor guidance.
- Update or replace affected installations according to Foxit guidance.
- Reduce handling of untrusted PDFs on affected endpoints until remediated.
Validation and detection
- Confirm installed Foxit PDF Reader versions across managed endpoints.
- Verify whether version 11.0.1.49938 is present.
- Review Foxit bulletin history for the applicable fixed release.
- Check EDR or email telemetry for suspicious PDF-opening events.
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-2021-34976 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
- Low
- CVSS
- 3.3 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
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:L/I:N/A:N1.81.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
3.3LowVector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- ZDI-21-1207CVE 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.