CVE-2025-43300 — An out-of-bounds write issue was addressed with improved bounds checking.¶
Key facts
CVE-2025-43300 is a Critical (10.0) vulnerability: An out-of-bounds write issue was addressed with improved bounds checking.. This entry ships a detection-only PoC and a Docker test lab. It is on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2025-08-21), confirming active exploitation in the wild.
Actively exploited — on the CISA KEV catalog
CVE-2025-43300 is listed on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2025-08-21), confirming exploitation in the wild. Federal remediation deadline: 2025-09-11. Prioritise patching and deploy the detection and prevention rules below.
| CVE | CVE-2025-43300 |
| Severity | Critical (10.0) |
| CISA KEV | Actively exploited (added 2025-08-21) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2025/CVE-2025-43300/ |
Details¶
English | 한국어
Description¶
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS 15.8.5, iOS 16.7.12 and iPadOS 16.7.12, iOS 18.6.2 and iPadOS 18.6.2, iPadOS 17.7.10, macOS Sequoia 15.6.1, macOS Sonoma 14.7.8, macOS Ventura 13.7.8. Processing a malicious image file may result in memory corruption. Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2025-43300 |
| Type | RCE |
| CVSS Score | 10.0 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2025/CVE-2025-43300/poc.py
Usage¶
# Run PoC against target
python3 poc.py --target <TARGET_URL>
# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>
⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.
Test Lab¶
This repository includes a Docker-based test environment with both vulnerable and patched applications.
Quick Start¶
# Clone and navigate to CVE directory
cd CVE-2025-43300
# Start both applications
docker-compose up -d
# Run tests
./run-tests.sh # Linux/Mac
./run-tests.ps1 # Windows PowerShell
Application Endpoints¶
| Application | URL | Status |
|---|---|---|
| Vulnerable App | http://localhost:8080 | Shows vulnerability |
| Patched App | http://localhost:8081 | Demonstrates fix |
Directory Structure¶
├── README.md # English documentation
├── README_KO.md # Korean documentation
├── poc.py # PoC detection script
├── docker-compose.yml # Container orchestration
├── run-tests.sh # Linux/Mac test runner
├── run-tests.ps1 # Windows test runner
├── vulnerable-app/ # Vulnerable version
│ ├── app.py
│ ├── Dockerfile
│ └── requirements.txt
└── patched-app/ # Fixed version
├── app.py
├── Dockerfile
└── requirements.txt
References¶
- https://support.apple.com/en-us/124925
- https://support.apple.com/en-us/124926
- https://support.apple.com/en-us/124927
- https://support.apple.com/en-us/124928
- https://support.apple.com/en-us/124929
- https://support.apple.com/en-us/125141
- https://support.apple.com/en-us/125142
- http://seclists.org/fulldisclosure/2025/Sep/10
- http://seclists.org/fulldisclosure/2025/Sep/14
- http://seclists.org/fulldisclosure/2025/Sep/52
- https://github.com/b1n4r1b01/n-days/blob/main/CVE-2025-43300.md
- https://github.com/cisagov/vulnrichment/issues/201
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-43300
Generated by PoC Generator on 2026-06-23T10:28:28.722384792
Frequently asked questions¶
What is CVE-2025-43300?¶
CVE-2025-43300 is a Critical (10.0) vulnerability: An out-of-bounds write issue was addressed with improved bounds checking.. This entry ships a detection-only PoC and a Docker test lab. It is on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2025-08-21), confirming active exploitation in the wild.
How do I detect CVE-2025-43300?¶
Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.
How do I block or mitigate CVE-2025-43300?¶
Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.
Is CVE-2025-43300 actively exploited?¶
Yes. CVE-2025-43300 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, added 2025-08-21, which means it has been exploited in the wild. CISA set a federal remediation deadline of 2025-09-11. Prioritise patching and deploy the detection and prevention rules above.
For authorized security testing and research only. See the full source and NVD record.