Security readout for executives and security teams
Plain-English summary
A malicious PDF or web-delivered document could run code in Foxit PDF Reader after a user opens it or visits a malicious page. The business risk is endpoint compromise through normal document handling, especially where users receive external PDFs.
Executive priority
Treat as a high-priority workstation exposure where Foxit PDF Reader is deployed. It is not wormable, but document-driven compromise can affect high-value users and external-facing teams.
Technical view
CVE-2021-34948 is a use-after-free in Foxit PDF Reader handling Square annotation objects. The flaw is tied to missing validation that an object still exists before operations continue. ZDI reports arbitrary code execution in the current process context. Affected version evidence names Foxit PDF Reader 11.0.0.49893.
Likely exposure
Exposure is most likely on workstations using Foxit PDF Reader 11.0.0.49893, especially users who open PDFs from email, web downloads, customer submissions, or shared drives.
Exploitation context
Sources state exploitation requires user interaction: opening a malicious file or visiting a malicious page. The provided bundle does not show CISA KEV listing or other evidence of active exploitation.
Researcher notes
The public details identify the vulnerable component and bug class but do not provide a fixed version in the supplied bundle. Avoid assuming patch details; validate against Foxit’s advisory page and local installed versions.
Mitigation direction
- Inventory Foxit PDF Reader installations and flag version 11.0.0.49893.
- Check Foxit security bulletins for the vendor-correct fixed release or guidance.
- Prioritize updates for users handling external or untrusted PDFs.
- Use attachment filtering, isolation, or safer viewers for untrusted PDFs until remediated.
Validation and detection
- Confirm whether endpoints have Foxit PDF Reader 11.0.0.49893 installed.
- Verify upgraded endpoints no longer report the affected version.
- Review email and web controls for delivery of suspicious PDF files.
- Check EDR alerts for abnormal child processes from Foxit PDF Reader.
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-2021-34948 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-21-1179CVE 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.