Kernel code execution via unchecked dead-port reference
Published Aug 24, 2021 · Updated Aug 3, 2024
Memory corruption in the Apple XNU kernel on iOS, iPadOS, macOS, and watchOS allows local users to execute code with kernel privileges. The ipc_right_copyin_two path fails to check an IP_DEAD return from ipc_port_copy_send, so it can use a Mach port right without acquiring the reference that keeps the object alive. Exploitation requires a malicious local application to manipulate Mach port state concurrently; success grants kernel execution, while an unsuccessful trigger can crash the operating system.
Summary
What happened
Memory corruption in the Apple XNU kernel on iOS, iPadOS, macOS, and watchOS allows local users to execute code with kernel privileges. The ipc_right_copyin_two path fails to check an IP_DEAD return from ipc_port_copy_send, so it can use a Mach port right without acquiring the reference that keeps the object alive. Exploitation requires a malicious local application to manipulate Mach port state concurrently; success grants kernel execution, while an unsuccessful trigger can crash the operating system.
The record
- CVE
- CVE-2021-30949
- Published
- Aug 24, 2021
- Updated
- Aug 3, 2024
- Vendor
- Apple
- Product
- iOS and iPadOS
- Classifications
- CWE-787, T1068
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 24, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=unspecified <15.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- XNU kernel use-after-free in mach_msg proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo