Security readout for executives and security teams
Plain-English summary
CVE-2021-34841 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. It is a workstation compromise risk, most relevant to phishing and document-handling workflows, not a remotely reachable server issue.
Executive priority
Prioritize remediation for user workstations handling external documents. The business risk is compromise through malicious PDFs, with potential confidentiality, integrity, and availability impact under the affected user context.
Technical view
The flaw affects Foxit PDF Reader 11.0.0.49893. It occurs in Annotation object handling and is associated with CWE-416. The source says Foxit fails to validate that an object exists before operating on it, allowing arbitrary code execution in the current process after user interaction.
Likely exposure
Exposure is likely where Foxit PDF Reader 11.0.0.49893 remains installed on endpoints, especially users who receive external PDFs or browse untrusted content. The bundle names only this version, so broader version impact should not be assumed without Foxit guidance.
Exploitation context
The source requires user interaction: opening a malicious file or visiting a malicious page. The bundle does not state active exploitation, and CISA KEV status is false. Treat this as a phishing-enabled endpoint code execution risk rather than proven in-the-wild exploitation.
Researcher notes
ZDI tracks this as ZDI-21-923 and ZDI-CAN-14022. The CVSS vector is AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H, reflecting local/user-assisted execution with high impact. The bundle does not provide exploit details, fixed versions, or evidence of active exploitation.
Mitigation direction
- Identify and upgrade or remove Foxit PDF Reader 11.0.0.49893 from managed endpoints.
- Check Foxit security bulletins for the supported fixed version and deployment guidance.
- Restrict risky PDF handling where upgrading cannot be completed promptly.
- Use endpoint controls to limit untrusted attachments and browser-delivered PDF content.
Validation and detection
- Query endpoint inventory for Foxit PDF Reader version 11.0.0.49893.
- Confirm remediated hosts no longer report the affected version.
- Review software deployment records against Foxit’s security bulletin guidance.
- Check endpoint telemetry for unexpected Foxit Reader process behavior after suspicious PDF activity.
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-2021-34841 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-21-923/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.