CVE-2023-32409
Apple Multiple Products WebKit Sandbox Escape Vulnerability
Description
CVE-2023-32409 is a high-severity sandbox escape vulnerability in Apple WebKit that affects Safari, iOS, iPadOS, macOS Ventura, tvOS, and watchOS. The flaw stems from insufficient bounds checking, which allows a remote attacker to break out of the Web Content sandbox. Apple has confirmed that CVE-2023-32409 may have been actively exploited prior to the release of patches in May 2023. CISA has added this WebKit vulnerability to its Known Exploited Vulnerabilities catalog, requiring remediation by June 12, 2023.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:NOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| apple | safari | < 16.5 |
| apple | ipados | >= 15.0, < 15.7.8; >= 16.0, < 16.5 |
| apple | iphone os | >= 15.0, < 15.7.8; >= 16.0, < 16.5 |
| apple | macos | >= 13.0, < 13.4 |
| apple | tvos | < 16.5 |
| apple | watchos | < 9.5 |
Multiple CVSS Assessments
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
References
- https://support.apple.com/en-us/HT213757(Vendor Advisory)
- https://support.apple.com/en-us/HT213758(Vendor Advisory)
- https://support.apple.com/en-us/HT213761(Vendor Advisory)
- https://support.apple.com/en-us/HT213762(Vendor Advisory)
- https://support.apple.com/en-us/HT213764(Vendor Advisory)
- https://support.apple.com/en-us/HT213842(Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-32409(US Government Resource)
Weakness Type
Insufficient Bounds Checking
CVE-2023-32409 results from insufficient bounds checking in Apple WebKit's handling of web content. The lack of adequate boundary validation allows a remote attacker to access memory outside the intended sandbox constraints, enabling an escape from the Web Content sandbox. No specific CWE has been assigned to this vulnerability by NVD.
Learn more: Apple Security Advisory HT213757
Impact Analysis
CVE-2023-32409 carries a CVSS v3.1 score of 8.6 (High), reflecting the significant risk posed by a sandbox escape in WebKit. The vulnerability is remotely exploitable without physical access via malicious web content, with low attack complexity and no authentication required. Critically, no user interaction is needed, and the scope is Changed, meaning the vulnerability can affect resources beyond the vulnerable WebKit component — specifically, it enables escape from the Web Content sandbox to access the broader operating system. While confidentiality impact is rated None and availability impact is None, the integrity impact is High, indicating that an attacker who escapes the sandbox can modify system resources and potentially chain this with other exploits for full device compromise. The EPSS score of 0.25% suggests exploitation is targeted rather than widespread, consistent with the sophisticated nature of sandbox escape exploits typically used in advanced attack chains.
Exploit Maturity
CISA has confirmed active exploitation of CVE-2023-32409 by adding it to the Known Exploited Vulnerabilities catalog, with a remediation deadline of June 12, 2023. Apple's own advisory acknowledges that this issue may have been actively exploited prior to patching. The relatively low EPSS score of 0.25% suggests that exploitation is targeted and likely used by advanced threat actors in sophisticated attack chains rather than in widespread automated campaigns. Sandbox escape vulnerabilities like CVE-2023-32409 are particularly valuable in exploit chains, as they are typically combined with an initial code execution vulnerability (such as CVE-2023-28204 or CVE-2023-32373, both patched in the same Apple updates) to achieve full device compromise.
Remediation
- Update all affected Apple platforms immediately as directed by CISA's KEV required action. Apply the following updates: iOS 16.5/iPadOS 16.5 or later, iOS 15.7.8/iPadOS 15.7.8 or later for older devices, macOS Ventura 13.4 or later, Safari 16.5 or later, tvOS 16.5 or later, and watchOS 9.5 or later.
- Prioritize mobile device updates across your organization using MDM (Mobile Device Management) solutions to ensure all managed iPhones, iPads, and Macs receive the security patches promptly. Enable automatic updates where possible.
- Restrict web browsing on unpatched devices by limiting access to untrusted websites through web content filtering or proxy solutions until patches can be applied, reducing exposure to malicious web content that could trigger the exploit.
- Monitor for indicators of compromise by reviewing device logs for unusual process behavior, unexpected sandbox escapes, or signs of spyware installation. Check for unauthorized profile installations or suspicious network connections originating from WebKit processes.
- Maintain ongoing WebKit patching discipline as Apple's browser engine is a frequent target for zero-day exploitation. Subscribe to Apple security advisories and establish rapid patch deployment processes for all Apple devices in your environment.
Technical Details
CVE-2023-32409 is a bounds checking deficiency in Apple's WebKit engine that enables a remote attacker to break out of the Web Content sandbox. The Web Content sandbox is a critical security boundary in Apple's architecture that isolates web rendering processes from the rest of the operating system. The CVSS vector (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N) reveals key characteristics: the Changed scope indicates the exploit crosses a security boundary (the sandbox), while the High integrity impact with no confidentiality or availability impact suggests the attacker gains the ability to modify resources outside the sandbox context. The fix involved improved bounds checks, indicating that the original vulnerability allowed out-of-bounds memory access that could be leveraged to manipulate sandbox enforcement mechanisms. This type of vulnerability is particularly significant in Apple's security model, where the Web Content sandbox is designed to be the primary defense layer against web-based attacks.
Frequently Asked Questions
Is CVE-2023-32409 being actively exploited?
Yes, CVE-2023-32409 has been actively exploited. Apple acknowledged that this issue may have been exploited prior to patch release, and CISA has added it to the Known Exploited Vulnerabilities catalog with a remediation deadline of June 12, 2023. The exploitation is believed to be targeted rather than widespread, consistent with its use in advanced attack chains.
What products are affected by CVE-2023-32409?
CVE-2023-32409 affects Apple Safari (before 16.5), iOS (before 16.5 and 15.7.8), iPadOS (before 16.5 and 15.7.8), macOS Ventura (before 13.4), tvOS (before 16.5), and watchOS (before 9.5). All devices running these Apple operating systems with WebKit are potentially vulnerable.
How do I fix CVE-2023-32409?
Update all affected Apple devices to the latest available operating system versions: iOS/iPadOS 16.5+ or 15.7.8+, macOS Ventura 13.4+, Safari 16.5+, tvOS 16.5+, and watchOS 9.5+. Use MDM solutions to deploy patches across managed devices and enable automatic updates.
How severe is CVE-2023-32409?
CVE-2023-32409 is rated High with a CVSS v3.1 score of 8.6 out of 10. It is a sandbox escape vulnerability requiring no authentication or user interaction, which can enable attackers to break out of WebKit's security boundary. It is especially dangerous when chained with other vulnerabilities for full device compromise.
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