CriticalCVE-2023-38606

    Apple Multiple Products Kernel Unspecified Vulnerability (CVE-2023-38606)

    Published In CISA KEV since Sources: pwn.watch, SingCERT, CVE.org

    What is affected, what to do

    This issue was addressed with improved state management. This issue is fixed in macOS Monterey 12.6.8, iOS 15.7.8 and iPadOS 15.7.8, iOS 16.6 and iPadOS 16.6, tvOS 16.6, macOS Big Sur 11.7.9, macOS Ventura 13.5, watchOS 9.6.

    The vulnerability is being actively exploited; treat it as a priority. Update Apple tvOS to version 16.6, Apple iOS and iPadOS to version 16.6, Apple macOS to version 13.5. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • Apple tvOS lt *..16.6
    • Apple iOS and iPadOS lt *..16.6
    • Apple macOS lt *..13.5
    • Apple iOS and iPadOS lt *..15.7
    • Apple macOS lt *..11.7
    • Apple macOS lt *..12.6
    • Apple watchOS lt *..9.6
    Fixed in
    • Apple tvOS 16.6
    • Apple iOS and iPadOS 16.6
    • Apple macOS 13.5
    • Apple iOS and iPadOS 15.7
    • Apple macOS 11.7
    • Apple macOS 12.6
    • Apple watchOS 9.6

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    5.5

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    5.5

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: pwn.watch, SingCERT, CVE.org

    2.9 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 86.9

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    190.98 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    actively exploitedSource: Apple (CVE.org), CSA/SingCERT How we classify
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    5.5 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    5.5
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    2.9 %
    Moderate — model estimates 1-10% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    86.9
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    Actively exploited
    Published
    In CISA KEV since

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This flaw lets an attacker tamper with sensitive kernel state. Its value to attackers is as a link in multi-stage exploit chains: once initial code execution is achieved, it is used to defeat kernel protections and anchor persistent, stealthy spyware implants. On its own the severity reads as moderate, since it requires local execution and user interaction or app execution, and exploitation likelihood is elevated rather than extreme. In practice, however, this class of bug serves targeted espionage against individuals with access to sensitive information, not broad ransomware operations, and CISA records no ransomware use. For KRITIS and NIS2 organisations, rate it high for managed Apple devices belonging to executives, admins and OT-access staff, and medium for the rest of the fleet. Because fixes have been available for a long time, any device still below the minimum builds is a hygiene and compliance failure that needs action.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Enforce the patch via MDM: The minimum versions are iOS/iPadOS 16.6, iOS/iPadOS 15.7.8 (for devices that cannot run iOS 16), macOS Ventura 13.5, macOS Monterey 12.6.8, macOS Big Sur 11.7.9, tvOS 16.6 and watchOS 9.6. Set an enforced update deadline in Intune, Jamf or Workspace ONE (Managed Software Update / DDM "enforce by date") and mark anything older as non-compliant.
      • Inventory exposed devices: Export every device below those builds from your MDM. Treat devices on iOS versions earlier than 15.7.1 as top priority, because Apple states that observed exploitation targeted exactly those releases.
      • Tighten Conditional Access: Block non-compliant iOS, iPadOS and macOS devices from M365, VPN, mail and internal apps until they update. This includes BYOD devices under app-protection policies, so set a minimum OS version there as well.
      • Fast-track high-value users: Contact executives, admins, staff with OT or control-room access and frequent travellers directly and have them update immediately. If compromise is suspected, retire the device rather than just patching it.
      • Handle devices that cannot be updated: Hardware that cannot reach any of the fixed builds must be retired or fully cut off from corporate resources.

    2. Runbook step 2

      Mitigation layers

      • Endpoint hardening (iOS/iPadOS/macOS): Enable Lockdown Mode for high-exposure staff. It shrinks the attack surface around message attachments, web technologies and inbound services, which makes the initial foothold that precedes a kernel exploit harder to obtain.
      • Application control: Exploitation requires a malicious app or an existing code-execution context. Restrict installs to managed apps via MDM, block enterprise sideloading and unapproved configuration profiles, and enforce Gatekeeper and SIP status on macOS through compliance checks.
      • IAM / least privilege: Mobile devices must never hold privileged sessions directly, such as domain admin, cloud global admin or OT remote maintenance. Route admin work through dedicated PAWs or jump hosts, and shorten session and token lifetimes for mobile clients.
      • Network segmentation: Keep BYOD and mobile Wi-Fi off production, OT and server VLANs. Place Apple TV and tvOS meeting-room devices in an isolated IoT segment with no routing into the corporate network.
      • DNS and proxy control: Force mobile traffic through DNS filtering or an SWG, using per-app VPN or a DNS settings payload, so that post-exploitation C2 traffic is visible and blockable.
      • Mobile Threat Defense: Tie an MTD agent such as Defender for Endpoint (iOS), Lookout or Zimperium into MDM compliance, so that jailbreak or integrity findings automatically revoke access.

    3. Runbook step 3

      Detection rules

      • MDM compliance query (Intune/KQL): This query lists iOS and iPadOS devices below the fixed build: IntuneDevices | where OS in ("iOS","iPadOS") | where parse_version(OSVersion) < parse_version("16.6") and not(OSVersion startswith "15.7.8") | project DeviceName, UserName, OSVersion, LastContact Build the equivalent query for macOS against 13.5, 12.6.8 and 11.7.9.
      • Forensic triage of suspect iOS devices: Take an iTunes backup or sysdiagnose and run the Mobile Verification Toolkit against it (mvt-ios check-backup). Look for unknown process names in DataUsage.sqlite or netusage.sqlite, unexpected attachments in sms.db, and gaps or deletions in logs. The context supplies no specific IOCs, so load public STIX IOC feeds.
      • macOS EDR/Unified Log: Watch for unsigned or ad-hoc-signed binaries making kernel-adjacent calls shortly after launch, and for unexplained kernel panics or reboots. Check the Unified Log with log show --predicate 'eventMessage CONTAINS "panic" OR subsystem == "com.apple.kernel"' --last 7d. A Sigma-style shape for Jamf Protect or Defender for Endpoint (macOS) is process.code_signature.signed: false AND parent.name NOT IN (Xcode, Terminal).
      • Network telemetry (Zeek/Suricata, DNS): Flag iOS and macOS clients resolving newly registered or rare domains outside Apple, MDM and known SaaS destinations, for example with dns.log | where client in mobile_subnet | stats dc(query) by query | where first_seen < 30d AND count < 3. Also flag unusually large uploads from the mobile VLAN to non-cloud destinations.
      • MTD/MDM integrity signals: Escalate jailbreak detections, unexpected configuration profiles or sudden MDM check-in gaps on high-value users as incidents, not merely as compliance drift.

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    This issue was addressed with improved state management. This issue is fixed in macOS Monterey 12.6.8, iOS 15.7.8 and iPadOS 15.7.8, iOS 16.6 and iPadOS 16.6, tvOS 16.6, macOS Big Sur 11.7.9, macOS Ventura 13.5, watchOS 9.6. An app may be able to modify sensitive kernel state. Apple is aware of a report that this issue may have been actively exploited against versions of iOS released before iOS 15.7.1.

    Source: pwn.watch, CSA/SingCERT, NVD (NIST), cvelistv5, CISA KEV Catalog, CVE.org (MITRE)

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    AppleiOS and iPadOS
    • < 16.6
    • < 15.7
    • 16.6
    • 15.7
    ApplemacOS
    • < 12.6
    • < 11.7
    • < 13.5
    • 12.6
    • 11.7
    • 13.5
    AppletvOS
    • < 16.6
    • 16.6
    ApplewatchOS
    • < 9.6
    • 9.6

    Vendors and products

    Affected operating systems

    Affected operating systems
    macOSapplemacos—
    Mobileappleiphone_os—
    Otherappleipados—
    Otherappletvos—
    Otherapplewatchos—

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CISA KEV CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited
    Apple (CVE.org)CVE.org (MITRE) (opens in a new tab)actively exploited
    CSA/SingCERTActive Exploitation of Zero-day Vulnerability in Apple Products (opens in a new tab)CSA/SingCERTactively exploited

    References & sources

    Embed badge

    Show the severity and KEV status of this vulnerability on your site – with a link back here. The image is updated hourly.

    Badge preview for CVE-2023-38606
    <a href="https://intel.neosec.eu/en/cve/CVE-2023-38606"><img src="https://intel.neosec.eu/badge/cve/CVE-2023-38606.svg?lang=en" alt="CVE-2023-38606 – NEOSEC Intel" height="20"></a>