CVE-2020-1909
📋 TL;DR
A use-after-free vulnerability in WhatsApp's iOS logging library could allow memory corruption, crashes, or potentially remote code execution. This affects WhatsApp and WhatsApp Business for iOS users running versions before 2.20.111. Exploitation requires a specific sequence of events including receiving an animated sticker while placing a video call on hold.
💻 Affected Systems
- WhatsApp for iOS
- WhatsApp Business for iOS
📦 What is this software?
Whatsapp by Whatsapp
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution allowing attacker to take full control of the device, access messages, contacts, and device data.
Likely Case
Application crashes and instability, potentially leading to denial of service for WhatsApp functionality.
If Mitigated
No impact if patched version is installed or if the specific trigger sequence doesn't occur.
🎯 Exploit Status
Exploitation requires specific timing and conditions, making reliable exploitation difficult but possible.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.20.111 and later
Vendor Advisory: https://www.whatsapp.com/security/advisories/2020/
Restart Required: Yes
Instructions:
1. Open App Store on iOS device. 2. Search for WhatsApp or WhatsApp Business. 3. Tap 'Update' if available. 4. Restart the app after update completes.
🔧 Temporary Workarounds
Disable animated stickers
iosPrevent receiving animated stickers which are part of the exploit chain
Avoid placing video calls on hold
iosDon't place WhatsApp video calls on hold while using the app
🧯 If You Can't Patch
- Uninstall vulnerable WhatsApp versions and use alternative messaging platforms
- Restrict WhatsApp usage to devices with updated versions only
🔍 How to Verify
Check if Vulnerable:
Check WhatsApp version in Settings > Help > App Info. If version is below 2.20.111, device is vulnerable.Check Version:
Not applicable - check via app interface on iOSVerify Fix Applied:
Confirm WhatsApp version is 2.20.111 or higher in Settings > Help > App Info.📡 Detection & Monitoring
Log Indicators:
- Unexpected WhatsApp crashes
- Memory corruption errors in system logs
- Anomalous memory usage by WhatsApp
Network Indicators:
- Unusual network traffic during WhatsApp video calls with sticker interactions
SIEM Query:
Not applicable for consumer mobile apps