CVE-2021-43188
📋 TL;DR
This vulnerability in JetBrains YouTrack Mobile for iOS allows attackers to bypass access token protection, potentially gaining unauthorized access to user accounts. It affects iOS users of YouTrack Mobile versions before 2021.2.
💻 Affected Systems
- JetBrains YouTrack Mobile
📦 What is this software?
Youtrack Mobile by Jetbrains
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal access tokens and gain full control over YouTrack accounts, accessing sensitive project data, manipulating issues, or performing unauthorized actions.
Likely Case
Attackers with physical access to the device or malware could extract access tokens to impersonate users and access their YouTrack data.
If Mitigated
With proper mobile device management and security controls, the risk is limited to devices already compromised by malware or physical attackers.
🎯 Exploit Status
Exploitation requires access to the iOS device filesystem, either through physical access or malware.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2021.2 or later
Vendor Advisory: https://blog.jetbrains.com/blog/2021/11/08/jetbrains-security-bulletin-q3-2021/
Restart Required: Yes
Instructions:
1. Open the App Store on your iOS device. 2. Search for 'YouTrack Mobile'. 3. If an update is available, tap 'Update'. 4. Alternatively, uninstall and reinstall the app to get the latest version.
🔧 Temporary Workarounds
Disable YouTrack Mobile on iOS
iosRemove the vulnerable app from iOS devices until patched.
Long-press the YouTrack Mobile app icon, then tap 'Remove App'
🧯 If You Can't Patch
- Implement mobile device management (MDM) to restrict app installations and enforce security policies.
- Use conditional access policies to require additional authentication for YouTrack access from mobile devices.
🔍 How to Verify
Check if Vulnerable:
Check the YouTrack Mobile app version in iOS Settings > General > iPhone Storage > YouTrack Mobile.Check Version:
Not applicable for iOS apps; check via Settings as described.Verify Fix Applied:
Verify the app version is 2021.2 or higher in iOS Settings.📡 Detection & Monitoring
Log Indicators:
- Unusual access patterns from iOS devices
- Multiple failed login attempts followed by successful access from new locations
Network Indicators:
- YouTrack API requests with stolen tokens from unexpected IP addresses
SIEM Query:
source="youtrack" AND (device_type="ios" OR user_agent CONTAINS "iOS") AND action="authentication" AND result="success" AND version<"2021.2"