CVE-2023-42852 – This is a logic vulnerability in Apple's WebKit... (How to Fix)

Q: What is the severity of CVE-2023-42852?

CVE-2023-42852 has a CVSS score of 8.8 (HIGH). This is a logic vulnerability in Apple's WebKit browser engine that allows arbitrary code execution when processing malicious web content. Attackers can exploit this by tricking users into visiting specially crafted websites, potentially taking full control of affected devices. All users of unpatched Apple devices with vulnerable versions are affected.

📋 TL;DR

This is a logic vulnerability in Apple's WebKit browser engine that allows arbitrary code execution when processing malicious web content. Attackers can exploit this by tricking users into visiting specially crafted websites, potentially taking full control of affected devices. All users of unpatched Apple devices with vulnerable versions are affected.

💻 Affected Systems

Products:

iOS
iPadOS
watchOS
macOS
Safari
tvOS

Versions: Versions prior to iOS 17.1, iPadOS 17.1, watchOS 10.1, iOS 16.7.2, iPadOS 16.7.2, macOS Sonoma 14.1, Safari 17.1, tvOS 17.1

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

Default Config Vulnerable: ⚠️ Yes

Notes: All default configurations are vulnerable. The vulnerability is in WebKit, which powers Safari and other Apple web rendering components.

📦 What is this software?

Macos by Apple

macOS is Apple's desktop and laptop operating system powering Mac computers used by millions of professionals, developers, creative professionals, and enterprise users worldwide. Built on a Unix foundation with the Darwin kernel and modern Cocoa frameworks, macOS delivers a seamless ecosystem integr...

Learn more about Macos →

Safari by Apple

View all CVEs affecting Safari →

Tvos by Apple

View all CVEs affecting Tvos →

Watchos by Apple

View all CVEs affecting Watchos →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete compromise of device with attacker gaining full control, data theft, persistence, and lateral movement within networks.

🟠

Likely Case

Malicious website executes code on victim's device, potentially stealing credentials, installing malware, or accessing sensitive data.

🟢

If Mitigated

Attack fails due to patched systems, web content filtering, or network segmentation limiting impact.

🌐 Internet-Facing: HIGH - Exploitation requires only visiting a malicious website, making internet-facing devices highly vulnerable.

🏢 Internal Only: MEDIUM - Internal users could be targeted via phishing or compromised internal websites.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires user interaction (visiting malicious website) but no authentication. No public exploit code is confirmed, but the high CVSS score suggests reliable exploitation is possible.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: iOS 17.1, iPadOS 17.1, watchOS 10.1, iOS 16.7.2, iPadOS 16.7.2, macOS Sonoma 14.1, Safari 17.1, tvOS 17.1

Vendor Advisory: https://support.apple.com/en-us/HT213982

Restart Required: Yes

Instructions:

1. Go to Settings > General > Software Update on iOS/iPadOS/watchOS/tvOS. 2. Install the latest available update. 3. For macOS, go to System Settings > General > Software Update. 4. For Safari on older macOS versions, update through the App Store.

🔧 Temporary Workarounds

Disable JavaScript

all

Temporarily disable JavaScript in Safari to prevent exploitation, though this breaks many websites.

Safari > Settings > Security > uncheck 'Enable JavaScript'

Use Alternative Browser

macOS

Use browsers not based on WebKit (like Firefox or Chrome on macOS) until patched.

🧯 If You Can't Patch

Implement strict web content filtering to block malicious sites
Use network segmentation to isolate vulnerable devices from critical resources

🔍 How to Verify

Check if Vulnerable:

Check device version in Settings > General > About > Software Version (iOS/iPadOS/watchOS/tvOS) or Apple menu > About This Mac (macOS).

Check Version:

sw_vers (macOS), system_profiler SPSoftwareDataType (macOS), or check Settings > General > About (iOS devices)

Verify Fix Applied:

Verify version matches or exceeds patched versions listed in affected_systems.versions.

📡 Detection & Monitoring

Log Indicators:

Unusual Safari/WebKit process crashes
Suspicious website accesses in browser history
Unexpected process execution following web browsing

Network Indicators:

Connections to known malicious domains serving exploit code
Unusual outbound traffic from Apple devices after web browsing

SIEM Query:

source="*safari*" OR process="WebKit" AND (event="crash" OR event="unexpected_execution")

📊 Metadata

CVE ID: CVE-2023-42852

CVSS v3 Score: 8.8 (HIGH)

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

Published: October 25, 2023

Last Updated: May 5, 2025

🔗 References

http://seclists.org/fulldisclosure/2023/Oct/19 Mailing List,Third Party Advisory
http://seclists.org/fulldisclosure/2023/Oct/22 Mailing List,Third Party Advisory
http://seclists.org/fulldisclosure/2023/Oct/23 Mailing List,Third Party Advisory
http://seclists.org/fulldisclosure/2023/Oct/24 Mailing List,Third Party Advisory
http://seclists.org/fulldisclosure/2023/Oct/25 Mailing List,Third Party Advisory
http://seclists.org/fulldisclosure/2023/Oct/27 Mailing List,Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/11/15/1 Mailing List
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RPPMOWFYZODONTA3RLZOKSGNR4DELGG2/ Mailing List,Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/S3O7ITSBZDHLBM5OG22K6RZAHRRTGECM/ Mailing List,Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZTCZGQPRDAOPP6NK4CIDJKIPMBWD5J7K/ Mailing List
https://security.gentoo.org/glsa/202401-33 Third Party Advisory
https://support.apple.com/en-us/HT213981 Release Notes,Vendor Advisory
https://support.apple.com/en-us/HT213982 Release Notes,Vendor Advisory
https://support.apple.com/en-us/HT213984 Release Notes,Vendor Advisory
https://support.apple.com/en-us/HT213986 Release Notes,Vendor Advisory
https://support.apple.com/en-us/HT213987 Release Notes,Vendor Advisory
https://support.apple.com/en-us/HT213988 Release Notes,Vendor Advisory
https://support.apple.com/kb/HT213984 Third Party Advisory
https://www.debian.org/security/2023/dsa-5557 Third Party Advisory
http://seclists.org/fulldisclosure/2023/Oct/19 Mailing List,Third Party Advisory
http://seclists.org/fulldisclosure/2023/Oct/22 Mailing List,Third Party Advisory
http://seclists.org/fulldisclosure/2023/Oct/23 Mailing List,Third Party Advisory
http://seclists.org/fulldisclosure/2023/Oct/24 Mailing List,Third Party Advisory
http://seclists.org/fulldisclosure/2023/Oct/25 Mailing List,Third Party Advisory
http://seclists.org/fulldisclosure/2023/Oct/27 Mailing List,Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/11/15/1 Mailing List
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RPPMOWFYZODONTA3RLZOKSGNR4DELGG2/ Mailing List,Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/S3O7ITSBZDHLBM5OG22K6RZAHRRTGECM/ Mailing List,Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZTCZGQPRDAOPP6NK4CIDJKIPMBWD5J7K/ Mailing List
https://security.gentoo.org/glsa/202401-33 Third Party Advisory
https://support.apple.com/en-us/HT213981 Release Notes,Vendor Advisory
https://support.apple.com/en-us/HT213982 Release Notes,Vendor Advisory
https://support.apple.com/en-us/HT213984 Release Notes,Vendor Advisory
https://support.apple.com/en-us/HT213986 Release Notes,Vendor Advisory
https://support.apple.com/en-us/HT213987 Release Notes,Vendor Advisory
https://support.apple.com/en-us/HT213988 Release Notes,Vendor Advisory
https://support.apple.com/kb/HT213984 Third Party Advisory
https://www.debian.org/security/2023/dsa-5557 Third Party Advisory

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