Security readout for executives and security teams
Plain-English summary
CVE-2021-31458 affects Foxit Reader 10.1.1.37576. A user who opens a malicious file or visits a malicious page could allow an attacker to run code inside the Foxit Reader process. The main business risk is endpoint compromise through document handling.
Executive priority
Treat this as a high-priority endpoint remediation issue where Foxit Reader is deployed. It enables code execution but requires user interaction, and the provided evidence does not show active exploitation. Focus first on users who regularly receive external documents.
Technical view
The flaw is in Foxit Reader handling of Annotation objects. The software fails to validate that an object exists before operating on it, mapped to CWE-416. ZDI states this can allow arbitrary code execution in the current process context after user interaction.
Likely exposure
Exposure is most likely on endpoints running Foxit Reader 10.1.1.37576, especially where users open externally supplied PDF files or browser-delivered documents. The provided sources do not identify other Foxit products or versions as affected.
Exploitation context
User interaction is required: the target must open a malicious file or visit a malicious page. The source bundle does not indicate CISA KEV listing or active exploitation in the wild, so active exploitation should not be claimed from this evidence.
Researcher notes
Do not broaden scope beyond Foxit Reader 10.1.1.37576 based on the provided data. ZDI identifies the affected component as Annotation object handling and describes a missing object-existence validation issue. No exploit steps or reliable active-exploitation signal are present in the source bundle.
Mitigation direction
- Inventory endpoints for Foxit Reader 10.1.1.37576.
- Review Foxit security bulletin for vendor-designated fixed versions or guidance.
- Update or remove affected Foxit Reader installations according to vendor guidance.
- Restrict handling of untrusted PDF files until remediation is complete.
- Prioritize systems used by high-risk users processing external documents.
Validation and detection
- Confirm installed Foxit Reader versions through endpoint inventory.
- Check vulnerability scanner results for CVE-2021-31458 coverage.
- Verify remediated systems no longer report version 10.1.1.37576.
- Review document-handling workflows for exposure to external PDFs.
- Confirm patch status against Foxit’s published security bulletin.
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-2021-31458 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-21-547/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.