Security readout for executives and security teams
Plain-English summary
CVE-2021-34951 is a low-severity information disclosure issue in Foxit PDF Reader. A user would need to open a malicious file or visit a malicious page. By itself it exposes limited sensitive information, but the advisory notes it could help an attacker when chained with other vulnerabilities.
Executive priority
Handle through normal endpoint patch management, with faster attention for teams processing untrusted documents. The rating is low because exploitation requires user interaction and only direct information disclosure is described, but chaining potential keeps it relevant.
Technical view
The flaw is in handling Annotation objects in Foxit PDF Reader 11.0.0.49893. It is caused by use of an uninitialized pointer, mapped to CWE-457, producing information disclosure. The source says it may be chained with other flaws to execute code in the current process context.
Likely exposure
Exposure is mainly desktop endpoints running Foxit PDF Reader 11.0.0.49893, especially where users handle external PDFs or web content. The provided sources do not identify other affected versions or platforms.
Exploitation context
User interaction is required. The source bundle does not show CISA KEV listing or other evidence of active exploitation. Treat it as a document-handling risk that becomes more important if paired with other Foxit or client-side vulnerabilities.
Researcher notes
Evidence is limited to the CVE entry, ZDI advisory, and Foxit bulletin landing page. The source bundle names Foxit PDF Reader 11.0.0.49893 and ZDI-CAN-14395. It does not provide exploit status, detailed patch version, or broader product impact.
Mitigation direction
- Inventory Foxit PDF Reader installations and identify version 11.0.0.49893.
- Check Foxit security bulletins for the applicable update or remediation.
- Update affected installations according to Foxit guidance when available.
- Limit opening PDFs or web content from untrusted sources on affected endpoints.
- Prioritize users who routinely handle external documents.
Validation and detection
- Confirm installed Foxit PDF Reader versions on managed endpoints.
- Review scanner findings for CVE-2021-34951 against Foxit Reader assets.
- Check whether affected endpoints have vendor-recommended updates applied.
- Confirm document-handling controls cover high-risk external PDFs and links.
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-457: 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-2021-34951 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
- Low
- CVSS
- 3.3 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
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:L/I:N/A:N1.81.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
3.3LowVector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- ZDI-21-1182CVE 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 of Uninitialized Variable
Use of Uninitialized Variable represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.