CVE-2021-47877
📋 TL;DR
GeoGebra Graphing Calculator 6.0.631.0 contains a denial of service vulnerability where attackers can crash the application by inputting an oversized buffer of 8000 repeated characters. This affects users of the vulnerable version who open malicious files or receive crafted input.
💻 Affected Systems
- GeoGebra Graphing Calculator
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Application becomes completely unresponsive and crashes, potentially causing data loss of unsaved work and disrupting educational or mathematical workflows.
Likely Case
Temporary application crash requiring restart, with potential loss of unsaved calculations or graphs.
If Mitigated
No impact if patched version is used or if input validation prevents oversized buffers.
🎯 Exploit Status
Exploit requires user interaction (opening malicious file or pasting content). Proof of concept available in exploit database.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 6.0.631.0
Vendor Advisory: https://www.geogebra.org
Restart Required: Yes
Instructions:
1. Open GeoGebra Graphing Calculator. 2. Go to Help > Check for Updates. 3. Follow prompts to install latest version. 4. Restart application.
🔧 Temporary Workarounds
Input validation configuration
allConfigure application or system to limit input field sizes
User education
allTrain users not to open untrusted GeoGebra files or paste unknown content
🧯 If You Can't Patch
- Restrict user permissions to prevent execution of untrusted GeoGebra files
- Implement application whitelisting to control which GeoGebra versions can run
🔍 How to Verify
Check if Vulnerable:
Check application version in Help > About. If version is 6.0.631.0, you are vulnerable.Check Version:
On Windows: Check Help > About. On macOS: GeoGebra > About GeoGebra. On Linux: Check application menu for version info.Verify Fix Applied:
Update to latest version and verify version number is higher than 6.0.631.0.📡 Detection & Monitoring
Log Indicators:
- Application crash logs
- Unexpected termination events
Network Indicators:
- No network indicators (local exploit)
SIEM Query:
EventID: 1000 (Application Error) with GeoGebra.exe in Windows Event Logs