CVE-2020-10003 – This vulnerability allows a local attacker to b... (How to Fix)

Q: What is the severity of CVE-2020-10003?

CVE-2020-10003 has a CVSS score of 7.8 (HIGH). This vulnerability allows a local attacker to bypass symlink path validation in Apple operating systems, potentially gaining elevated privileges. It affects macOS, iOS, iPadOS, tvOS, and watchOS before specific security updates. Attackers must have local access to the system to exploit this flaw.

📋 TL;DR

This vulnerability allows a local attacker to bypass symlink path validation in Apple operating systems, potentially gaining elevated privileges. It affects macOS, iOS, iPadOS, tvOS, and watchOS before specific security updates. Attackers must have local access to the system to exploit this flaw.

💻 Affected Systems

Products:

macOS
iOS
iPadOS
tvOS
watchOS

Versions: Versions before macOS Big Sur 11.0.1, iOS 14.2, iPadOS 14.2, tvOS 14.2, watchOS 7.1

Operating Systems: macOS, iOS, iPadOS, tvOS, watchOS

Default Config Vulnerable: ⚠️ Yes

Notes: All default configurations of affected Apple operating systems are vulnerable. No special configuration required for exploitation.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Local privilege escalation to root/system-level access, allowing complete system compromise and persistence.

🟠

Likely Case

Local user gains elevated privileges beyond their normal permissions, potentially accessing sensitive data or modifying system files.

🟢

If Mitigated

With proper access controls and patching, impact is limited to denial of service or minimal privilege escalation within user's existing context.

🌐 Internet-Facing: LOW - Requires local access to exploit, not directly exploitable over network.

🏢 Internal Only: HIGH - Local attackers (including malicious insiders or compromised accounts) can exploit this to gain elevated privileges on affected systems.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ✅ No

Complexity: LOW

Exploit requires local access but is relatively straightforward once local access is obtained. Public disclosure includes technical details that could facilitate exploitation.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: macOS Big Sur 11.0.1, iOS 14.2, iPadOS 14.2, tvOS 14.2, watchOS 7.1

Vendor Advisory: https://support.apple.com/en-us/HT211928

Restart Required: Yes

Instructions:

1. Open System Preferences > Software Update. 2. Install available updates. 3. Restart device when prompted. For iOS/iPadOS: Settings > General > Software Update. For tvOS: Settings > System > Software Updates. For watchOS: iPhone Watch app > General > Software Update.

🔧 Temporary Workarounds

Restrict local user access

all

Limit local user accounts and implement strict access controls to reduce attack surface.

Monitor symlink creation

linux

Implement file system monitoring for suspicious symlink creation in sensitive directories.

sudo auditctl -w /etc -p wa -k sensitive_symlinks
sudo auditctl -w /usr -p wa -k sensitive_symlinks

🧯 If You Can't Patch

Implement strict principle of least privilege for all user accounts
Deploy endpoint detection and response (EDR) solutions to monitor for privilege escalation attempts

🔍 How to Verify

Check if Vulnerable:

Check OS version: macOS: sw_vers -productVersion, iOS/iPadOS: Settings > General > About > Version, tvOS: Settings > General > About > Version, watchOS: iPhone Watch app > General > About > Version

Check Version:

macOS: sw_vers -productVersion

Verify Fix Applied:

Verify version is equal to or newer than: macOS 11.0.1, iOS 14.2, iPadOS 14.2, tvOS 14.2, watchOS 7.1

📡 Detection & Monitoring

Log Indicators:

Unexpected privilege escalation events
Suspicious symlink creation in system directories
Failed authorization attempts followed by successful privileged operations

Network Indicators:

None - local exploitation only

SIEM Query:

source="*audit.log" AND (event_type="SYMLINK" OR event_type="PATH") AND user!="root" AND path IN ("/etc/*", "/usr/*", "/var/*")

📊 Metadata

CVE ID: CVE-2020-10003

CVSS v3 Score: 7.8 (HIGH)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-59

Published: December 8, 2020

Last Updated: November 21, 2024

🔗 References

http://seclists.org/fulldisclosure/2020/Dec/32 Mailing List,Third Party Advisory
https://support.apple.com/en-us/HT211928 Vendor Advisory
https://support.apple.com/en-us/HT211929 Vendor Advisory
https://support.apple.com/en-us/HT211930 Vendor Advisory
https://support.apple.com/en-us/HT211931 Vendor Advisory
http://seclists.org/fulldisclosure/2020/Dec/32 Mailing List,Third Party Advisory
https://support.apple.com/en-us/HT211928 Vendor Advisory
https://support.apple.com/en-us/HT211929 Vendor Advisory
https://support.apple.com/en-us/HT211930 Vendor Advisory
https://support.apple.com/en-us/HT211931 Vendor Advisory

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