CriticalCVE-2024-44309

    Apple Multiple Products Cross-Site Scripting (XSS) Vulnerability (CVE-2024-44309)

    Published In CISA KEV since Sources: CVE.org, Debian, pwn.watch, Red Hat

    What is affected, what to do

    A cookie management issue was addressed with improved state management. This issue is fixed in Safari 18.1.1, iOS 17.7.2 and iPadOS 17.7.2, iOS 18.1.1 and iPadOS 18.1.1, macOS Sequoia 15.1.1, visionOS 2.1.1.

    The vulnerability is being actively exploited; treat it as a priority. Update Apple Safari to version 18.1.1, Apple iOS and iPadOS to version 17.7.2, Apple iOS and iPadOS to version 18.1.1. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • Apple Safari lt *..18.1.1
    • Apple iOS and iPadOS lt *..17.7.2
    • Apple iOS and iPadOS lt *..18.1.1
    • Apple macOS lt *..15.1.1
    • Apple visionOS lt *..2.1.1
    Fixed in
    • Apple Safari 18.1.1
    • Apple iOS and iPadOS 17.7.2
    • Apple iOS and iPadOS 18.1.1
    • Apple macOS 15.1.1
    • Apple visionOS 2.1.1

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

    Metrics

    6.3

    Priority

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

    Source: NVD, CVSS v3

    6.3

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: CVE.org, Debian, pwn.watch, Red Hat

    22.0 %

    EPSS score

    Elevated — model estimates 10-50% exploitation likelihood.

    Source: FIRST EPSS, percentile 97.7

    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
    214.70 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) 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
    6.3 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
    6.3
    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
    22.0 %
    Elevated — model estimates 10-50% 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
    97.7
    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
    CISA assessment (SSVC)
    Exploitation: active · not automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 23 November 2024
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-79

    Response and mitigation

    Why act now?

    Prioritisation rationale

    The base severity looks moderate because exploitation needs user interaction and the direct impact is limited. However, the flaw is reachable over the network without authentication, Apple has flagged active use against Intel Macs, and it sits among the CVEs with very high exploitation likelihood. WebKit cookie and state-management bugs suit targeted drive-by and watering-hole campaigns against selected users, often chained with other browser bugs fixed in the same release. CISA does not flag ransomware use. If you run a managed Apple fleet, patch within days, starting with Intel Macs and accounts holding privileged or tenant-wide SaaS access. Treat it as high wherever a hijacked session would open a path into NIS2-relevant systems.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Push and enforce patches via MDM: macOS Sequoia 15.1.1, Safari 18.1.1 (standalone update for older macOS releases running Safari 18), iOS/iPadOS 18.1.1, iOS/iPadOS 17.7.2 for devices on the 17.x track, and visionOS 2.1.1. In Jamf, Intune, Kandji or similar, set an enforced update deadline (24-48 h) with a forced restart.
      • Intel Macs first: Apple reports possible active exploitation on Intel-based Macs. Filter inventory by CPU architecture and patch those devices first, especially those used by executives, admins and staff with access to critical SaaS or OT portals.
      • Tie compliance to Conditional Access: Mark unpatched devices (Safari < 18.1.1, macOS < 15.1.1, iOS/iPadOS < 17.7.2 or < 18.1.1) as non-compliant. Block them from the IdP, mail and crown-jewel apps until they update.
      • Invalidate sessions: The flaw sits in cookie management and enables XSS, so session hijacking is plausible. For users whose devices were unpatched and who show suspicious browsing, revoke refresh tokens and web sessions (Entra "Revoke sessions", Okta "Clear user sessions").
      • Notify users: Send a short advisory to Apple users: install the update now, and avoid opening links from unknown messages in Safari until then.

    2. Runbook step 2

      Mitigation layers

      • Endpoint (macOS): Until patched, set Chrome or Firefox as the default browser on affected Macs, since they use their own engines rather than WebKit. Apps embedding WKWebView (Mail, messengers, help viewers) stay exposed, so this lowers the risk without removing it.
      • Endpoint (iOS/iPadOS): Every iOS browser runs on WebKit, so switching browsers does nothing there. For high-risk users, enable Lockdown Mode until the update lands, or temporarily disable JavaScript in Safari via an MDM restriction.
      • Network / secure web gateway: For Apple devices, block or isolate (remote browser isolation) the categories newly registered, unrated and uncategorised domains. Enforce protective DNS against known malvertising and phishing infrastructure.
      • IAM: Shorten web session lifetimes and enable token binding or Continuous Access Evaluation. Require phishing-resistant MFA (FIDO2) for privileged accounts so a stolen cookie loses value quickly.
      • Application side (your own web apps): Set cookies with HttpOnly, Secure and SameSite=Strict/Lax, and deploy a strict Content-Security-Policy. This limits XSS impact regardless of the browser bug.

    3. Runbook step 3

      Detection rules

      • Vulnerability inventory (Defender for Endpoint): DeviceTvmSoftwareVulnerabilities | where CveId == "CVE-2024-44309" | summarize by DeviceName, SoftwareName, SoftwareVersion. To cross-check via osquery, run SELECT bundle_short_version FROM apps WHERE bundle_identifier='com.apple.Safari'; and flag versions < 18.1.1.
      • Session replay at the IdP: Look for the same session ID appearing from multiple ASNs or with changing user agents. KQL: SigninLogs | summarize ASNs=dcount(AutonomousSystemNumber), UAs=dcount(UserAgent) by SessionId, UserPrincipalName | where ASNs > 1 or UAs > 1.
      • EDR process ancestry (macOS): Flag unusual children or file writes from com.apple.WebKit.WebContent or Safari, such as sh, osascript, curl, or writes to ~/Library/LaunchAgents. Sigma shape: ParentImage|contains: 'WebKit.WebContent' AND Image|endswith: ['/sh','/bash','/osascript','/curl'].
      • Proxy and network telemetry (Zeek/Suricata/SWG): Watch for Safari user agents hitting very young domains (< 30 days) or rare ones (< 3 clients org-wide), followed shortly by SaaS logins from foreign IP ranges.
      • Retro-hunt: Sweep proxy and IdP logs from mid-November 2024 onward for Intel Macs matching the patterns above. Start with high-exposure user groups.

    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

    A cookie management issue was addressed with improved state management. This issue is fixed in Safari 18.1.1, iOS 17.7.2 and iPadOS 17.7.2, iOS 18.1.1 and iPadOS 18.1.1, macOS Sequoia 15.1.1, visionOS 2.1.1. Processing maliciously crafted web content may lead to a cross site scripting attack. Apple is aware of a report that this issue may have been actively exploited on Intel-based Mac systems.

    Source: cvelistv5, Debian Security Advisories, pwn.watch, NVD (NIST), CISA KEV Catalog, CVE.org (MITRE), redhat_csaf

    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
    • < 18.1.1
    • < 17.7.2
    • 18.1.1
    • 17.7.2
    ApplemacOS
    • < 15.1.1
    • 15.1.1
    AppleSafari
    • < 18.1.1
    • 18.1.1
    ApplevisionOS
    • < 2.1.1
    • 2.1.1
    applesafari
    • < 18.1.1
    • 18.1.1

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebiandebian_linux11.0
    Linuxdebianwebkit2gtkbookworm
    macOSapplemacos—
    Mobileappleiphone_os—
    Otherappleipados—
    Otherapplevisionos—

    Weakness classes (CWE)

    • CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

      Base

      The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

      Entry at MITRE CWE-79

    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

    References & sources

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