Security readout for executives and security teams
Plain-English summary
A malicious PDF or web page could cause Foxit PDF Reader 11.0.0.49893 to run attacker-controlled code when a user opens it. This is high risk for endpoints that routinely handle external PDFs, but the source bundle does not show active exploitation.
Executive priority
Treat as a high-priority endpoint remediation item where Foxit PDF Reader is deployed. Business urgency is driven by potential code execution through routine document handling, moderated by required user interaction and no sourced active-exploitation evidence.
Technical view
The flaw is in Foxit PDF Reader Annotation object handling. The issue is described as missing validation of an object before operations, mapped to CWE-416, allowing arbitrary code execution in the current process with required user interaction.
Likely exposure
Exposure is limited to installations of Foxit PDF Reader 11.0.0.49893 identified in the source bundle. Highest concern is user workstations receiving untrusted PDFs or browsing untrusted content.
Exploitation context
Exploitation requires a victim to visit a malicious page or open a malicious file. The bundle marks KEV as false and provides no cited evidence of active exploitation.
Researcher notes
ZDI identifies this as ZDI-CAN-14531 / ZDI-21-931. Analysis should stay scoped to Foxit PDF Reader 11.0.0.49893 unless additional vendor data confirms broader impact.
Mitigation direction
- Inventory Foxit PDF Reader deployments and identify version 11.0.0.49893.
- Review Foxit security bulletins for the vendor-fixed version and update guidance.
- Prioritize remediation on endpoints handling external PDFs or email attachments.
- Use user-awareness controls for unsolicited PDFs until vendor guidance is applied.
Validation and detection
- Confirm whether Foxit PDF Reader 11.0.0.49893 exists on managed endpoints.
- Verify remediated systems no longer report the affected version.
- Check vulnerability scanner findings against the exact product and version.
- Review endpoint telemetry for suspicious PDF Reader crashes or child processes.
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-2021-34849 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
- https://www.foxit.com/support/security-bulletins.htmlCVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-21-931/CVE reference · x_refsource_MISC
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.