CVE-2021-38563

CRITICAL

An issue was discovered in Foxit PDF Reader before 11.0.1 and PDF Editor before 11.0.1. It mishandles situations in which an array size (derived from a /Size entry) is smaller than the maximum indi...

Affects 2 products across 2 vendors.

CVSS 3.19.8
EPSS1.1%
Percentile65th
PatchPatched
CVSS Vector — Plain English Remotely exploitable over the network, low complexity, no authentication required, no user interaction needed, impact contained to the vulnerable component, full confidentiality impact, full integrity impact, full availability impact.
CWE Weakness Definitions
CWE-129: CWE-129
Related Attack Patterns (CAPEC)
CAPEC-100 Overflow Buffers
via CWE-129

Mapping is CWE-to-CAPEC per MITRE CAPEC 3.9.

◆ AI Analysis — automated analysis, not human-reviewed

A critical vulnerability in Foxit PDF Reader and PDF Editor versions prior to 11.0.1 allows for a NULL pointer dereference, out-of-bounds read, or write due to improper handling of array sizes in PDF files.

BSID: BS-2021-GLOBAL-305244-C • Model: /workspace/models/qwen2.5-coder-32b-instruct-bf16 • Confidence: HIGH

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Frequently Asked Questions
What is CVE-2021-38563?
A critical vulnerability in Foxit PDF Reader and PDF Editor versions prior to 11.0.1 allows for a NULL pointer dereference, out-of-bounds read, or write due to improper handling of array sizes in PDF files.
What is the CVSS score for CVE-2021-38563?
CVE-2021-38563 has CVSS 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS: 1.1%.
Is CVE-2021-38563 actively exploited?
No confirmed active exploitation of CVE-2021-38563 as of 2026-05-30.
How do I remediate CVE-2021-38563?
Priority: IMMEDIATE. Advisory: https://www.foxitsoftware.com/support/security-bulletins.php PSIRT: [email protected]
What systems are affected by CVE-2021-38563?
CVE-2021-38563 affects Foxit Pdf Reader; Foxitsoftware Pdf Editor.
Vulnerability Details
CVE IDCVE-2021-38563
BSIDBS-2021-GLOBAL-305244-C BreachSpider Global ID
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published2021-08-11
Last Modified2024-11-21
ICS Relevance0%
Weakness (CWE)
CWE-129
SourceNVD
Official Description

An issue was discovered in Foxit PDF Reader before 11.0.1 and PDF Editor before 11.0.1. It mishandles situations in which an array size (derived from a /Size entry) is smaller than the maximum indirect object number, and thus there is an attempted incorrect array access (leading to a NULL pointer dereference, or out-of-bounds read or write).

Source: NIST NVD / MITRE CVE Database

Attack Vector Analysis — CITED Relevance

An attacker can exploit this vulnerability by crafting a malicious PDF file with a specially crafted array size, leading to a NULL pointer dereference, out-of-bounds read, or write. This could potentially allow for arbitrary code execution or denial of service.

Exploitation Likelihood: HIGH

Affected Products
VendorProductAffected Versions
Foxit Pdf Reader ≤ 11.0.0.0510
Foxitsoftware Pdf Editor ≤ 11.0.0.0510
Remediation
View Vendor Advisory →

Remediation Priority: IMMEDIATE

Vendor PSIRT: [email protected]
Threat Intelligence
● Threat Intelligence Validated: October 2026 | Threat Age: 1891 Days
CISA known-exploitedNot in KEV catalog
Public ExploitNot confirmed
PoC CodeNot confirmed
AI Enrichment Record — provenance & audit hash
Model/workspace/models/qwen2.5-coder-32b-instruct-bf16
ConfidenceHIGH
Enriched At2026-05-24
SHA-512 Audit Hash8ba34ad4f88f01a010c328480d8b2e563922c51588e16c48138a0ac226229850c15644c5c84a5ae9e08e784a20679de825c2a759c7f5ea97800fad7b70f9cb81
Related CVEs affecting Foxit
CVE-2009-0837 10.0 Stack-based buffer overflow in Foxit Reader 3.0 before Build 1506, including ... CVE-2022-28104 9.8 Foxit PDF Editor v11.3.1 was discovered to contain an arbitrary file upload v... CVE-2022-24955 9.8 Foxit PDF Reader before 11.2.1 and Foxit PDF Editor before 11.2.1 have an Unc... CVE-2022-24954 9.8 Foxit PDF Reader before 11.2.1 and Foxit PDF Editor before 11.2.1 have a Stac... CVE-2017-14458 8.8 An exploitable use-after-free vulnerability exists in the JavaScript engine o...
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