CVE-2025-14022
📋 TL;DR
LINE client for iOS versions before 15.4 has a critical SSL/TLS certificate validation bypass vulnerability in an integrated financial SDK. This allows man-in-the-middle attackers to intercept or modify encrypted communications for a significant portion of network traffic. All iOS LINE users with vulnerable versions are affected.
💻 Affected Systems
- LINE for iOS
📦 What is this software?
Line by Linecorp
⚠️ Risk & Real-World Impact
Worst Case
Attackers can intercept sensitive financial transactions, authentication credentials, private messages, and personal data transmitted through the LINE app, potentially leading to account takeover, financial fraud, and data theft.
Likely Case
Network-adjacent attackers on public Wi-Fi or compromised networks can intercept LINE communications, potentially capturing login credentials, messages, and financial data.
If Mitigated
With proper network segmentation and certificate pinning, risk is limited to users on untrusted networks without additional security controls.
🎯 Exploit Status
Exploitation requires network adjacency (same network as victim). No authentication needed. Standard MITM tools can exploit this vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 15.4 and later
Vendor Advisory: https://hackerone.com/reports/2853445
Restart Required: Yes
Instructions:
1. Open the App Store on iOS device
2. Search for 'LINE'
3. Tap 'Update' if available
4. Ensure version is 15.4 or higher
5. Restart the LINE application
🔧 Temporary Workarounds
Avoid Untrusted Networks
allPrevent exploitation by avoiding public Wi-Fi and untrusted networks where MITM attacks are more likely.
Use VPN
allRoute all LINE traffic through a trusted VPN to encrypt communications end-to-end and prevent local network MITM attacks.
🧯 If You Can't Patch
- Discontinue use of LINE app on iOS until patched, use web version or other platforms instead
- Implement network-level SSL inspection and certificate validation monitoring to detect MITM attempts
🔍 How to Verify
Check if Vulnerable:
Check LINE app version in iOS Settings > General > iPhone Storage > LINE, or within LINE app settings. If version is below 15.4, the device is vulnerable.Check Version:
No command line option. Check via iOS Settings or within LINE app settings menu.Verify Fix Applied:
Confirm LINE app version is 15.4 or higher in app settings. Test with SSL/TLS validation tools to ensure certificate validation is functioning properly.📡 Detection & Monitoring
Log Indicators:
- Unusual certificate validation failures
- Multiple SSL/TLS handshake failures from same device
- Certificate authority mismatches in network logs
Network Indicators:
- Unexpected SSL/TLS certificate changes for LINE domains
- MITM proxy detection between client and LINE servers
- Abnormal certificate chain validation patterns
SIEM Query:
source="network_traffic" app="LINE" (ssl_validation="failed" OR cert_chain_unusual="true")