Security readout for executives and security teams
Plain-English summary
CVE-2021-31453 is a high-severity Foxit Reader flaw that can let an attacker run code if a user opens a malicious file or visits a malicious page. The known affected version is Foxit Reader 10.1.1.37576. This is primarily an endpoint and document-handling risk, not a server-side remote takeover.
Executive priority
Treat this as a priority workstation patching issue. It has high impact if exploited, but requires user interaction and has no confirmed active exploitation in the provided sources. Focus on rapid inventory and updating affected Foxit Reader installations.
Technical view
The flaw is in Foxit Reader's handling of XFA Forms. Sources describe missing validation of an object's existence before operations, associated with CWE-416, allowing code execution in the current process. Exploitation requires user interaction. The source bundle names Foxit Reader 10.1.1.37576 as affected and cites ZDI-21-542.
Likely exposure
Organizations are exposed where users run Foxit Reader 10.1.1.37576 and receive or open untrusted PDFs or related web content. Exposure is most relevant on workstations, VDI images, and shared systems used for document review.
Exploitation context
The sources do not show CISA KEV listing or confirmed active exploitation. Exploitation is user-assisted: a target must open a malicious file or visit a malicious page. Successful exploitation could run attacker-controlled code with the privileges of the Foxit Reader process.
Researcher notes
ZDI tracked this as ZDI-CAN-13092 and advisory ZDI-21-542. The CVSS vector is local attack vector with required user interaction, despite the advisory describing remote attackers. No CPEs are supplied, so vulnerability management should use software inventory and version checks rather than relying only on CPE matching.
Mitigation direction
- Inventory endpoints for Foxit Reader 10.1.1.37576.
- Check Foxit's security bulletin for the fixed release and update path.
- Prioritize upgrades for users who handle external documents.
- Limit opening untrusted PDFs until affected installs are remediated.
- Use email and web controls to quarantine suspicious document lures.
Validation and detection
- Confirm installed Foxit Reader versions through endpoint inventory.
- Check whether version 10.1.1.37576 remains deployed anywhere.
- Review Foxit security bulletins for remediation status.
- Search EDR and mail telemetry for suspicious PDF delivery patterns.
- Verify upgraded systems still support required legitimate XFA workflows.
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-2021-31453 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.foxitsoftware.com/support/security-bulletins.phpCVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-21-542/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.