CVE-2025-55029
📋 TL;DR
This vulnerability in Firefox for iOS allows malicious scripts to bypass the popup blocker, enabling attackers to open excessive new tabs. This could lead to denial of service by consuming device resources and disrupting user experience. Only Firefox for iOS users with versions below 142 are affected.
💻 Affected Systems
- Firefox for iOS
📦 What is this software?
Firefox by Mozilla
⚠️ Risk & Real-World Impact
Worst Case
Complete browser unresponsiveness and device performance degradation due to resource exhaustion from infinite tab spawning, potentially requiring app or device restart.
Likely Case
Browser becomes slow or unresponsive due to multiple popup tabs opening, forcing users to close Firefox or restart their device to regain functionality.
If Mitigated
Minimal impact with proper popup blocking settings and updated browser version, though some temporary disruption may occur before tabs are closed.
🎯 Exploit Status
Exploitation requires visiting a malicious website but no user interaction beyond that. The vulnerability is publicly documented in Mozilla's advisory.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firefox for iOS 142
Vendor Advisory: https://www.mozilla.org/security/advisories/mfsa2025-68/
Restart Required: Yes
Instructions:
1. Open the App Store on your iOS device. 2. Search for Firefox. 3. Tap Update next to Firefox. 4. Wait for installation to complete. 5. Restart Firefox browser.
🔧 Temporary Workarounds
Enable Strict Popup Blocker
allConfigure Firefox to block all popups, though this may not fully prevent the bypass.
Use Alternative Browser
allTemporarily switch to Safari or another browser until Firefox is updated.
🧯 If You Can't Patch
- Avoid visiting untrusted websites and use browser extensions that block malicious scripts.
- Regularly close unused tabs and monitor browser performance for unusual behavior.
🔍 How to Verify
Check if Vulnerable:
Open Firefox on iOS, go to Settings > About Firefox, check if version is below 142.Check Version:
Not applicable for iOS; check via app settings.Verify Fix Applied:
After updating, confirm version is 142 or higher in Settings > About Firefox.📡 Detection & Monitoring
Log Indicators:
- Multiple tab creation events in rapid succession
- Browser crash or freeze logs
Network Indicators:
- Multiple requests to same malicious domain for popup content
SIEM Query:
Not typically applicable for client-side browser vulnerabilities on mobile devices.