Here is some resources about macOS/iOS system security.

exploit writeup

https://blog.pangu.io/

https://bugs.chromium.org/p/project-zero/issues/list

https://talosintelligence.com/vulnerability_reports#disclosed

CVE modules POC/writeup link
CVE-2015-???? Kernel https://github.com/kpwn/tpwn
http://nirvan.360.cn/blog/?p=469
https://www.blackhat.com/docs/eu-15/materials/eu-15-Todesco-Attacking-The-XNU-Kernal-In-El-Capitain.pdf
CVE-2016-???? XPC https://marcograss.github.io/security/apple/xpc/2016/06/17/containermanagerd-xpc-array-oob.html
CVE-2016-1758&CVE-2016-1828 Kernel https://bazad.github.io/2016/05/mac-os-x-use-after-free/
CVE-2016-1824 IOHIDFamily https://marcograss.github.io/security/apple/cve/2016/05/16/cve-2016-1824-apple-iohidfamily-racecondition.html
CVE-2016-1825 IOHIDFamily https://bazad.github.io/2017/01/physmem-accessing-physical-memory-os-x/
CVE-2016-1865 Kernel https://marcograss.github.io/security/apple/cve/2016/07/18/cve-2016-1865-apple-nullpointers.html
CVE-2016-1722 syslogd https://blog.zimperium.com/analysis-of-ios-os-x-vulnerability-cve-2016-1722/
CVE-2016-1757 Kernel https://googleprojectzero.blogspot.com/2016/03/race-you-to-kernel.html
https://papers.put.as/papers/macosx/2016/SyScan360_SG_2016_-_Memory_Corruption_is_for_wussies.pdf
http://turingh.github.io/2016/04/03/CVE-2016-1757%E7%AE%80%E5%8D%95%E5%88%86%E6%9E%90/
https://turingh.github.io/2016/04/19/CVE-2016-1757%E5%88%A9%E7%94%A8%E7%A8%8B%E5%BA%8F%E5%88%86%E6%9E%90/
CVE-2016-4633 Intel Graphics Driver https://marcograss.github.io/security/apple/cve/2016/07/21/cve-2016-4633-apple-graphics-another-osx-bug.html
CVE-2016-4673 CoreGraphics https://marcograss.github.io/security/apple/cve/macos/ios/2016/11/21/cve-2016-4673-apple-coregraphics.html
CVE-2016-7595 CoreText https://security.tencent.com/index.php/blog/msg/111
CVE-2017-13861 IOSurface https://siguza.github.io/v0rtex/
https://paper.seebug.org/472/
CVE-2017-13868 Kernel https://bazad.github.io/2018/03/a-fun-xnu-infoleak/
CVE-2018-4124 CoreText https://blog.zecops.com/vulnerabilities/analyzing-the-ios-telugu-crash-part-i/
CVE-2018-4184 sandbox https://ubrigens.com/posts/linking_a_microphone.html
CVE-2018-4185 Kernel https://bazad.github.io/2018/04/kernel-pointer-crash-log-ios/
CVE-2018-4229&CVE-2020-3854 sandbox https://ubrigens.com/posts/sandbox_initialisation_bypasses.html
CVE-2018-4248 libxpc https://bazad.github.io/2018/07/xpc-string-leak/
CVE-2018-4280 libxpc https://github.com/bazad/blanket
CVE-2018-4331&CVE-2018-4332&CVE-2018-4343 Heimdal https://bazad.github.io/2018/11/introduction-userspace-race-conditions-ios/
CVE-2018-4407 kernel https://securitylab.github.com/research/apple-xnu-icmp-error-CVE-2018-4407
CVE-2018-4415 CoreAnimation https://ssd-disclosure.com/ssd-advisory-ios-macos-safari-sandbox-escape-via-quartzcore-heap-overflow/
CVE-2018-4431 Kernel https://ssd-disclosure.com/ssd-advisory-ios-macos-kernel-task_inspect-information-leak/
CVE-2019-6225 Kernel https://blogs.360.cn/post/IPC%20Voucher%20UaF%20Remote%20Jailbreak%20Stage%202.html
https://googleprojectzero.blogspot.com/2019/08/in-wild-ios-exploit-chain-5.html
https://googleprojectzero.blogspot.com/2019/01/voucherswap-exploiting-mig-reference.html
http://highaltitudehacks.com/2020/06/01/from-zero-to-tfp0-part-1-prologue/
http://highaltitudehacks.com/2020/06/01/from-zero-to-tfp0-part-2-a-walkthrough-of-the-voucher-swap-exploit/
CVE-2019-6231 CoreAnimation https://www.fortinet.com/blog/threat-research/detailed-analysis-of-macos-ios-vulnerability-cve-2019-6231
CVE-2019-8507 CoreAnimation https://www.fortinet.com/blog/threat-research/detailed-analysis-mac-os-vulnerability-cve-2019-8507
CVE-2019-8549 Power Management https://ssd-disclosure.com/ssd-advisory-ios-powerd-uninitialized-mach-message-reply-to-sandbox-escape-and-privilege-escalation/
CVE-2019-8605 Kernel https://googleprojectzero.blogspot.com/2019/12/sockpuppet-walkthrough-of-kernel.html
CVE-2019-8635 AMD https://www.trendmicro.com/en_us/research/19/f/cve-2019-8635-double-free-vulnerability-in-apple-macos-lets-attackers-escalate-system-privileges-and-execute-arbitrary-code.html
CVE-2019-8794&CVE-2019-8795&CVE-2019-8797 Kernel&AVEVideoEncoder&Audio https://ssd-disclosure.com/ssd-advisory-via-ios-jailbreak-sandbox-escape-and-kernel-r-w-leading-to-rce/
CVE-2020-3847&CVE-2020-3848 CoreBluetooth https://blogs.360.cn/post/macOS_Bluetoothd_0-click.html
CVE-2020-3919 IOHIDFamily https://alexplaskett.github.io/CVE-2020-3919/
CVE-2020-9771 sandbox https://theevilbit.github.io/posts/cve_2020_9771/
https://theevilbit.github.io/posts/reversing_cve_2020_9771/
CVE-2020-9964 IOSurfaceAccelerator https://muirey03.blogspot.com/2020/09/cve-2020-9964-ios-infoleak.html
CVE-2020-9967 Kernel https://alexplaskett.github.io/CVE-2020-9967/
CVE-2020-9968 sandbox https://blog.xpnsec.com/we-need-to-talk-about-macl/
CVE-2020-9971 libxpc https://xlab.tencent.com/en/2021/01/11/cve-2020-9971-abusing-xpc-service-to-elevate-privilege/
CVE-2020-9979 Assets https://blog.chichou.me/2020/08/06/x-site-escape-part-ii-look-up-a-shell-in-the-dictionary/
CVE-2020-9992 IDE Device Support https://blog.zimperium.com/c0ntextomy-lets-debug-together-cve-2020-9992/
CVE-2020-27897 Kernel https://www.zerodayinitiative.com/blog/2020/12/9/cve-2020-27897-apple-macos-kernel-oob-write-privilege-escalation-vulnerability
CVE-2020-27932 Kernel https://worthdoingbadly.com/specialreply/
CVE-2020-27935 XNU https://github.com/LIJI32/SnatchBox
CVE-2020-27949 Kernel https://github.com/seemoo-lab/dtrace-memaccess_cve-2020-27949
CVE-2020-27950 Kernel https://www.synacktiv.com/publications/ios-1-day-hunting-uncovering-and-exploiting-cve-2020-27950-kernel-memory-leak.html
CVE-2020-9905 Kernel https://blog.zecops.com/vulnerabilities/from-a-comment-to-a-cve-content-filter-strikes-again/
CVE-2021-1758 FontParser https://starlabs.sg/advisories/21-1758/
CVE-2021-1782 Kernel https://github.com/ModernPwner/cicuta_virosa
https://www.synacktiv.com/publications/analysis-and-exploitation-of-the-ios-kernel-vulnerability-cve-2021-1782
CVE-2021-1790 FontParser https://starlabs.sg/advisories/21-1790/

opensource tools

iOS/MacOS Kernelcache/Extensions analysis tool:

https://github.com/lilang-wu/p-joker

macOS 10.13 kernel fuzzer using multiple different methods:

https://github.com/FSecureLABS/OSXFuzz

static analysis tool for analyzing the security of Apple kernel drivers:

https://github.com/alibaba-edu/Driver-Security-Analyzer

a framework is for fuzzing OSX kernel vulnerability based on passive inline hook mechanism in kernel mode:

https://github.com/SilverMoonSecurity/PassiveFuzzFrameworkOSX

bug hunting techniques

attack kernel graphics driver:

Attacking the macOS Kernel Graphics Driver

Don't Trust Your Eye: Apple Graphics Is Compromised!

LLDBFuzzer:

Debug for Bug: Crack and Hack Apple Core by Itself

LynxFuzzer:

Improving Mac OS X Security Through Gray Box Fuzzing Technique

Port Syzkaller to Support macOS XNU Fuzzing:

Drill Apple Core: Up and Down - Fuzz Apple Core Component in Kernel and User Mode for Fun and Profit