CVE-2020-9948
📋 TL;DR
CVE-2020-9948 is a type confusion vulnerability in Safari's WebKit engine that allows malicious web content to trigger memory corruption. Successful exploitation could lead to arbitrary code execution with the privileges of the Safari process. This affects all users running vulnerable versions of Safari on macOS, iOS, and iPadOS.
💻 Affected Systems
- Safari
- iOS
- iPadOS
- macOS
📦 What is this software?
Safari by Apple
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise via remote code execution leading to data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Attackers could execute arbitrary code in the browser context to steal cookies, session tokens, or credentials, and potentially pivot to other systems.
If Mitigated
With proper network segmentation and endpoint protection, impact could be limited to the affected browser session without lateral movement.
🎯 Exploit Status
Exploitation requires user interaction (visiting a malicious website) but no authentication. Type confusion vulnerabilities in browsers are commonly exploited in the wild.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Safari 14.0
Vendor Advisory: https://support.apple.com/HT211845
Restart Required: Yes
Instructions:
1. Open System Preferences > Software Update on macOS. 2. Install all available updates. 3. For iOS/iPadOS, go to Settings > General > Software Update. 4. Restart the device after installation.
🔧 Temporary Workarounds
Disable JavaScript
allTemporarily disable JavaScript in Safari to prevent exploitation, though this will break most websites.
Use Alternative Browser
allSwitch to a non-WebKit based browser until Safari is updated.
🧯 If You Can't Patch
- Implement network filtering to block known malicious domains and restrict web browsing to trusted sites only.
- Deploy endpoint detection and response (EDR) solutions to detect and block exploitation attempts.
🔍 How to Verify
Check if Vulnerable:
Check Safari version: Safari > About Safari. If version is below 14.0, the system is vulnerable.Check Version:
On macOS: defaults read /Applications/Safari.app/Contents/Info.plist CFBundleShortVersionStringVerify Fix Applied:
Verify Safari version is 14.0 or higher after applying updates.📡 Detection & Monitoring
Log Indicators:
- Unusual Safari crashes, unexpected process creation from Safari, suspicious JavaScript execution patterns
Network Indicators:
- Connections to known malicious domains from Safari, unusual outbound traffic patterns
SIEM Query:
source="safari" AND (event_type="crash" OR process_name="*shell*" OR cmdline="*bash*")🔗 References
- http://seclists.org/fulldisclosure/2020/Nov/18
- http://www.openwall.com/lists/oss-security/2020/11/23/3
- https://security.gentoo.org/glsa/202012-10
- https://support.apple.com/HT211845
- https://www.debian.org/security/2020/dsa-4797
- http://seclists.org/fulldisclosure/2020/Nov/18
- http://www.openwall.com/lists/oss-security/2020/11/23/3
- https://security.gentoo.org/glsa/202012-10
- https://support.apple.com/HT211845
- https://www.debian.org/security/2020/dsa-4797
