Threat reportVulnerabilityTL-2026-4713
Breaking the Sound Barrier, Part II: Exploiting CVE-2024-54529 (macOS CoreAudio coreaudiod type confusion, PoC public)
Breaking the Sound Barrier, Part II (TL-2026-4713), also tracked as Breaking the Sound Barrier Part II, is a high-severity software vulnerability scored CVSS 7.8, first published 2026-10-29. It has no confirmed attribution, affects Apple macOS (CoreAudio / Audio framework, coreaudiod) - CVE-2024-54529, references 2 CVEs (CVE-2024-54529, CVE-2025-31235), maps to 5 MITRE ATT&CK techniques (T1106, T1211, T1499.004), and is covered by 9 detection rules and 16 indicators of compromise.
- CVSS
- 7.8/10High
- CVEs
- 2Referenced vulnerabilities
- Techniques
- 5MITRE ATT&CK
- Actors
- 0Not attributed
- Detection rules
- 9SPL · KQL · Sigma
- IOCs
- 16Indicators of compromise
Key facts for TL-2026-4713
- Threat ID
- TL-2026-4713
- Also known as
- Breaking the Sound Barrier Part II, CoreAudioFuzz
- Severity
- HIGH
- CVSS
- 7.8 (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
- Status
- PATCHED
- Category
- VULNERABILITY
- First published
- Last reviewed
- Attribution confidence
- LOW
- Motivation
- UNKNOWN
- Detection rules
- 9
- Indicators of compromise
- 16
Malware and tooling in Breaking the Sound Barrier, Part II
Malware and tooling: Guard Malloc (PreScribble), Jackalope, TinyInst
How Breaking the Sound Barrier, Part II works
Google Project Zero published a full exploitation write-up and open-source PoC for CVE-2024-54529, a type confusion in the com.apple.audio.audiohald Mach service of macOS coreaudiod that lets an app execute code outside its sandbox or with elevated privileges. Apple patched it in December 2024; no in-the-wild exploitation is reported.
CVE-2024-54529 is a type confusion in the com.apple.audio.audiohald Mach service hosted by the coreaudiod daemon (CoreAudio / Audio framework). Part I of the research (published 2025-05-09) notes the service is reachable from sandboxed processes such as Safari's GPU process, and that it exposes control of audio hardware, so it normally runs with elevated privileges. Multiple Mach message handlers, for example _XIOContext_Fetch_Workgroup_Port, look up a HALS_Object in the HALS_ObjectMap using an attacker-supplied object ID and then operate on it as an 'ioct' (IOContext) object without validating its real type. The code dereferences a pointer at offset 0x68 of the object and performs a virtual call at offset 0x168 of the pointed-to structure, so an attacker who controls that data controls the call target.
In the Project Zero exploit (Dillon Franke, Google Information Security Engineering), exploitation requires a three-level pointer chain: offset 0x68 of the confused object must point to attacker-controlled memory, whose offset 0x0 points to a fake vtable, whose offset 0x168 holds the target address. Heap grooming uses the HALS_Object_SetPropertyData_DPList API, which accepts serialized property lists and allocates CFArray, CFDictionary, CFString and CFData objects with controlled content. An 'ngne' object type (0x308 bytes, created only at startup) has an uninitialized 6-byte gap at offset 0x68; the last 2 bytes are zeroed because of compiler alignment of an adjacent short field. The crafted plist is persisted to /Library/Preferences/Audio/com.apple.audio.DeviceSettings.plist. The type confusion is first triggered to crash coreaudiod; on restart CASettingsStorage::RefreshSettings loads the plist from disk and CASettingsStorage::SaveSettings makes a copy, writes it to disk and frees the copy, so freed attacker data is reused by ngne allocations in non-zeroed malloc_small regions (malloc_tiny zeroing defeated the original spray). The vulnerability is then re-triggered against the ngne object whose pointer chain now points into attacker data. A return-oriented-programming chain stored in UTF-16 CFString objects (to avoid invalid UTF-8 bytes), entered via an xchg rsp, rax stack-pivot gadget and using gadgets from CoreAudio in the dyld shared cache (constant addresses until reboot), issues raw syscalls inside the coreaudiod process. The demonstration payload opens and writes /Library/Preferences/Audio/malicious.txt.
The researcher built a custom object dumper using Ivan Fratric's TinyInst Hook API to enumerate HALS_ObjectMap linked lists, used IDAPython scripts to find code paths writing to the critical offset after CopyObjectByObjectID calls, used Guard Malloc with PreScribble (0xAA fill) to confirm uninitialized-memory use, and used the XSystem_Get_Object_Info handler to enumerate ngne objects on demand. The PoC in the p0tools repository (exploit.mm, build_rop.py, run_exploit.py, reset-devices.sh, plus cve-2024-54529-poc-macos-sequoia-15.0.1.c) was demonstrated on macOS Sequoia 15.0.1 and is Intel (x86-64) specific; its README recommends SIP disabled for debugging. Running it makes the audio system unresponsive, causes repeated coreaudiod crashes and leaves thousands of spurious dummy audio devices in the audio configuration; run_exploit.py backs up the original configuration to default-plist.plist and reset-devices.sh restores it. Apple Silicon would additionally require correctly signing the pointers in the chain and the ROP gadgets (pointer authentication), which the PoC does not address.
The bug was reported to Apple on 2024-10-09 and Apple fixed it ('a logic issue was addressed with improved checks') in macOS Sequoia 15.2, Sonoma 14.7.2 and Ventura 13.7.2 on 2024-12-11, crediting Dillon Franke working with Google Project Zero. NVD scores it CVSS 3.1 7.8 (HIGH) and CISA SSVC lists exploitation as PoC. The article also references CVE-2025-31235, a related double free in coreaudiod found with the same knowledge-driven fuzzing (Jackalope and TinyInst) and fixed in macOS Sequoia 15.5, Sonoma 14.7.6, Ventura 13.7.6 and iPadOS 17.7.7; NVD scores it 6.5 MEDIUM (availability impact, 'unexpected system termination'), SSVC exploitation none. No threat-actor use, CISA KEV listing or network IOCs were found in the sources.
MITRE ATT&CK techniques used in TL-2026-4713
Execution
T1106 Native API; T1559 Inter-Process Communication
Stealth
T1211 Exploitation for Stealth
Impact
T1499.004 Application or System Exploitation
Resource Development
Affected products and versions in Breaking the Sound Barrier, Part II
- Apple — macOS (CoreAudio / Audio framework, coreaudiod) - CVE-2024-54529
Vulnerable versions: Ventura 13.0 to before 13.7.2; Sonoma 14.0 to before 14.7.2; Sequoia 15.0 to before 15.2
Fixed in: Ventura 13.7.2; Sonoma 14.7.2; Sequoia 15.2 - Apple — macOS / iPadOS (coreaudiod) - CVE-2025-31235 double free
Vulnerable versions: Ventura before 13.7.6; Sonoma 14.0 to before 14.7.6; Sequoia 15.0 to before 15.5; iPadOS before 17.7.7
Fixed in: Ventura 13.7.6; Sonoma 14.7.6; Sequoia 15.5; iPadOS 17.7.7
Remediation for Breaking the Sound Barrier, Part II
Patches
- CVE-2024-54529: macOS Sequoia 15.2, Sonoma 14.7.2, Ventura 13.7.2 (Apple HT 121839/121840/121842)
- CVE-2025-31235: macOS Sequoia 15.5, Sonoma 14.7.6, Ventura 13.7.6, iPadOS 17.7.7 (Apple 122716/122717/122718)
Immediate actions
- Update macOS to Sequoia 15.2 or later, Sonoma 14.7.2 or later, Ventura 13.7.2 or later
- Update to macOS 15.5 / 14.7.6 / 13.7.6 (iPadOS 17.7.7) or later to also cover CVE-2025-31235
- Hunt for unexpected modification of /Library/Preferences/Audio/com.apple.audio.DeviceSettings.plist and for default-plist.plist or malicious.txt in /Library/Preferences/Audio/
- Hunt for repeated coreaudiod crashes (EXC_BAD_ACCESS), restarts, thousands of dummy audio devices, and anomalous child processes or network connections from coreaudiod
Workarounds
- No vendor workaround documented; apply the patch
Longer-term hardening
- Monitor Mach service abuse and unusual com.apple.audio.audiohald clients with EDR
- Restrict installation and execution of untrusted local apps via MDM and Gatekeeper policy
- Prefer Apple Silicon hardware where pointer authentication raises exploitation cost
CVEs associated with Breaking the Sound Barrier, Part II
Weaknesses (CWE) in Breaking the Sound Barrier, Part II
Timeline of Breaking the Sound Barrier, Part II
- Dillon Franke reports the CoreAudio type confusion to Apple (per Project Zero Part I)
- Apple releases macOS Sequoia 15.2, Sonoma 14.7.2 and Ventura 13.7.2 fixing CVE-2024-54529 (credit: Dillon Franke working with Google Project Zero)
- NVD publishes CVE-2024-54529 with CVSS 3.1 base score 7.8 (HIGH)
- Google Project Zero publishes Part I (knowledge-driven fuzzing of coreaudiod) and open-sources the CoreAudioFuzz harness in p0tools
- CVE-2025-31235 (coreaudiod double free, CVSS 6.5) published; fixed in macOS 15.5, 14.7.6, 13.7.6 and iPadOS 17.7.7
- Apple updates the macOS Sequoia 15.2 advisory entry for CVE-2024-54529
- Google Project Zero publishes Part II exploitation write-up; CVE-2024-54529 PoC exploit (exploit.mm, build_rop.py, run_exploit.py) released in p0tools
- NVD last modifies CVE-2024-54529 and CVE-2025-31235 records; CISA SSVC lists CVE-2024-54529 exploitation as PoC and CVE-2025-31235 as none
Sources cited for Breaking the Sound Barrier, Part II
- Breaking the Sound Barrier, Part II: Exploiting CVE-2024-54529 (Dillon Franke, Google Project Zero)
- Breaking the Sound Barrier, Part I: Fuzzing CoreAudio with Mach Messages (Dillon Franke, Google Project Zero)
- googleprojectzero/p0tools - CoreAudioFuzz (PoC and fuzzing harness)
- CoreAudioFuzz exploit README (run flow, artifacts, reset-devices.sh)
- NVD - CVE-2024-54529
- NVD - CVE-2025-31235
- Apple - About the security content of macOS Sequoia 15.2
- Apple - About the security content of macOS Sonoma 14.7.2
- Apple - About the security content of macOS Ventura 13.7.2
- Full Disclosure - APPLE-SA-2024-12 macOS Sequoia 15.2
- Full Disclosure - APPLE-SA-2024-12 macOS Ventura 13.7.2
- googleprojectzero/Jackalope (coverage-guided fuzzer)
- googleprojectzero/TinyInst (dynamic instrumentation library)
Detection coverage for TL-2026-4713
As of 2026-10-29, Threadlinqs Intelligence publishes 9 detection rule(s) for TL-2026-4713 across Splunk SPL, Microsoft KQL and Sigma, covering 16 indicator(s) of compromise. The whole corpus is readable without an account; a free account unlocks full detection query text in Splunk SPL, Microsoft KQL and Sigma; paid tiers add raw indicator values, correlation and the MCP server. Threadlinqs MCP server · View plans.