CriticalCVE-2024-27834

Apple Multiple Products Improper Authentication Vulnerability (CVE-2024-27834)

Published 14.05.2024Last modified 04.11.2026In CISA KEV since 04.11.2026Sources: pwn.watch, CVE.org, Red Hat, Debian

Actively exploited
Source: pwn.watch How we classify

What is affected, what to do

The issue was addressed with improved checks. This issue is fixed in Safari 17.5, iOS 16.7.8 and iPadOS 16.7.8, iOS 17.5 and iPadOS 17.5, macOS Sonoma 14.5, tvOS 17.5, watchOS 10.5.

The vulnerability is being actively exploited; treat it as a priority. Update Apple Safari to version 17.5, Apple iOS and iPadOS to version 16.7.8, Apple iOS and iPadOS to version 17.5. Immediate actions, mitigation and detection rules are in the runbook below.

Affected: Apple Safari lt *..17.5
Apple iOS and iPadOS lt *..16.7.8
Apple iOS and iPadOS lt *..17.5
Apple macOS lt *..14.5
Apple tvOS lt *..17.5
Apple watchOS lt *..10.5
Fixed in: Apple Safari 17.5
Apple iOS and iPadOS 16.7.8
Apple iOS and iPadOS 17.5
Apple macOS 14.5
Apple tvOS 17.5
Apple watchOS 10.5

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, CVE.org, Red Hat, Debian

0.6 %

EPSS score

Low — model estimates < 1% exploitation likelihood.

Source: FIRST EPSS, percentile 48.8

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: 151.58 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: pwn.watch 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: 0.6 %; Low — model estimates < 1% 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: 48.8; High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
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: 14.05.2024
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: 04.11.2026
CISA assessment (SSVC): Exploitation: active · not automatable · Technical impact: partial; Source: CISA Vulnrichment, as of 4 November 2026
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-287

Response and mitigation

Why act now?

Prioritisation rationale

This flaw is not an entry point on its own. It requires an attacker who already holds an arbitrary read/write primitive and serves as a chain link to defeat the Pointer Authentication hardware mitigation. That is why the vector shows local access with low privileges and integrity-only impact, and why mass-exploitation likelihood is assessed as moderate. CISA lists no known ransomware use. Its realistic use is in targeted browser and mobile exploit chains aimed at selected high-value individuals. Scored against your exposure, it is a high-urgency compliance gap for the general fleet because the fix has long been available. For devices used by executives, administrators and critical-infrastructure roles, treat it as critical and close it immediately.

01
Runbook step 1
Immediate response (0-24 h)
- Enforce patch level via MDM: Bring all managed Apple devices to the fixed releases: iOS/iPadOS 17.5, or 16.7.8 for devices that cannot move to 17, macOS Sonoma 14.5, Safari 17.5 on older macOS releases, tvOS 17.5 and watchOS 10.5. These fixes have been out for a long time, so any affected device is an overdue patch-policy exception. Later major releases also include the fix.
- Reconcile inventory: Export every device below those versions from your MDM (Intune, Jamf, Kandji etc.). Separately chase devices outside MDM: BYOD, meeting-room Apple TVs and kiosk iPads.
- Gate access on compliance: Activate Conditional Access or a compliance policy with a minimum OS version. Unpatched devices lose access to mail, VPN and SaaS until they are updated.
- Prioritise high-risk users: Update devices belonging to executives, admins, staff with OT or critical-infrastructure access, and people in press- or government-facing roles first. If compromise is suspected, capture a sysdiagnose or backup for forensics before wiping.
- Retire devices with no update path: Remove devices that cannot reach 16.7.8 or 17.5 from corporate access.
02
Runbook step 2
Mitigation layers
- Endpoint hardening: Enable Lockdown Mode for exposed users, via MDM profile or guided setup. Among other things it disables WebKit JIT, which shrinks the attack surface for the upstream memory-corruption primitives this PAC bypass depends on.
- Browser layer (macOS): Where immediate updating is impossible, block Safari via configuration profile or Jamf restricted software and mandate a separately patched browser. Note that apps embedding WKWebView still use system WebKit. On iOS/iPadOS every browser is WebKit-based, so patching is the only real fix.
- Network/web filtering: Use DNS or proxy filtering to block newly registered and uncategorised domains for mobile devices. Exploit chains of this type are typically delivered through crafted web pages or links in messages.
- Segmentation: Put Apple TVs and unmanaged Apple devices in an isolated VLAN with no reach into management networks, AD/Entra endpoints or OT segments.
- IAM/least privilege: Remove local admin rights from standard macOS users. Allow privileged access only from patched, compliant devices (phishing-resistant MFA plus device compliance).
03
Runbook step 3
Detection rules
- MDM/inventory query (compliance gap): Example KQL against Intune data: IntuneDevices | where OS has_any ("iOS","macOS") | extend v=parse_version(OSVersion) | where v < parse_version("17.5") and v != parse_version("16.7.8"). Treat the output as your work queue, and sanity-check branch versions manually.
- EDR process ancestry (macOS): Alert when com.apple.WebKit.WebContent or Safari spawns shells or LOLBins. Sigma shape: ParentImage|endswith: 'com.apple.WebKit.WebContent' AND Image|endswith: ['/sh','/zsh','/bash','/osascript','/curl','/python3']. The data source is Endpoint Security Framework exec events.
- Crash reports: Look for clusters of WebContent crashes with EXC_BAD_ACCESS or the note "possible pointer authentication failure". Locations: ~/Library/Logs/DiagnosticReports/*.ips on macOS, and analytics data inside sysdiagnose on iOS. Repeated crashes after visiting the same URL strongly suggest failed exploitation attempts.
- Unified log / sandbox: Run log show --predicate 'process == "com.apple.WebKit.WebContent" AND eventMessage CONTAINS "deny"' --last 7d to surface unusual renderer sandbox violations. These are typical of escape attempts once a read/write primitive is obtained.
- Mobile forensics/network: On suspect iOS devices, run the Mobile Verification Toolkit (MVT) against current public IOC sets. In Zeek or proxy logs, correlate Safari user agents making first contact with young domains, followed by anomalous outbound traffic from the same device.

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

The issue was addressed with improved checks. This issue is fixed in Safari 17.5, iOS 16.7.8 and iPadOS 16.7.8, iOS 17.5 and iPadOS 17.5, macOS Sonoma 14.5, tvOS 17.5, watchOS 10.5. An attacker with arbitrary read and write capability may be able to bypass Pointer Authentication.

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

Affected products

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

Affected products
		Affected versions	Fixed in
Apple	iOS and iPadOS	`< 16.7.8` `< 17.5`	`16.7.8` `17.5`
Apple	macOS	`< 14.5`	`14.5`
Apple	Safari	`< 17.5`	`17.5`
Apple	tvOS	`< 17.5`	`17.5`
Apple	watchOS	`< 10.5`	`10.5`
apple	safari	`< 17.5`	`17.5`
webkitgtk	webkitgtk	`< 2.44.2`	`2.44.2`
wpewebkit	wpe_webkit	`< 2.44.2`	`2.44.2`

Vendors and products

Affected operating systems

Affected operating systems

Linux	debian	webkit2gtk	`bookworm`
Linux	debian	webkit2gtk	`bullseye`
macOS	apple	macos	—
Mobile	apple	iphone_os	—
Other	fedoraproject	fedora	`39`
Other	fedoraproject	fedora	`40`
Other	apple	ipados	—
Other	apple	tvos	—
Other	apple	watchos	—

Weakness classes (CWE)

CWE-287Improper Authentication
Class
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
Entry at MITRE CWE-287

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 Catalog	CISA Known Exploited Vulnerability (opens in a new tab)cisa.gov	actively exploited	04.11.2026

References & sources

support.apple.comen-us/120896
support.apple.comen-us/120898
support.apple.comen-us/120901
support.apple.comen-us/120902
support.apple.comen-us/120903
support.apple.comAbout the security content of iOS 17.5 and iPadOS 17.5 (CVE-2024-27834)pwn-watch
support.apple.comen-us/HT214101x_transferred, Vendor advisory
support.apple.comen-us/HT214106x_transferred, Vendor advisory
support.apple.comen-us/HT214104x_transferred, Vendor advisory
support.apple.comen-us/HT214103x_transferred, Vendor advisory
support.apple.comen-us/HT214102x_transferred, Vendor advisory
seclists.orgfulldisclosure/2024/May/17x_transferred, Mailing list
openwall.comlists/oss-security/2024/05/21/1x_transferred, Mailing list
seclists.orgfulldisclosure/2024/May/10x_transferred, Mailing list
seclists.orgfulldisclosure/2024/May/9x_transferred, Mailing list
seclists.orgfulldisclosure/2024/May/12x_transferred, Mailing list
seclists.orgfulldisclosure/2024/May/16x_transferred, Mailing list
lists.fedoraproject.orgarchives/list/package-announce@lists.fedoraproject.org/message/…x_transferred, Mailing list
lists.fedoraproject.orgarchives/list/package-announce@lists.fedoraproject.org/message/…x_transferred, Mailing list
support.apple.comkb/HT214106

Changes to this CVE

Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

04.11.2026CISA KEV entry updated9119a7d8…
4 individual changes: Date Added, Due Date, Required Action, Vulnerability Name
Show 4 original changes
Individual changes of this event as published by NVD
Type Action Before After
Date Added added
—
2026-11-04
Due Date added
—
2026-11-04
Required Action added
—
2026-11-04
Vulnerability Name added
—
2026-11-04
Source identifier: 9119a7d8-5eab-497f-8521-727c672e3725

Individual changes of this event as published by NVD
Type	Action	Before	After
Date Added	added	—	2026-11-04
Due Date	added	—	2026-11-04
Required Action	added	—	2026-11-04
Vulnerability Name	added	—	2026-11-04

04.11.2026Record modifiedCISA ADP

CISA assessment (SSVC): exploitation: active, automatable: no

New references:

Show 4 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-27834
Reference	added	—	https://www.sekoia.com/blog/poisoned-source-apt29-watering-holes-targets-mobile-devices-with-n-day-exploits
SSVC assessment	removed	{"id":"CVE-2024-27834","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-11-04T17:36:46.499968Z"}	—
SSVC assessment	added	—	{"id":"CVE-2024-27834","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-11-04T20:14:40.746813Z"}

Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

04.11.2026Record modifiedCISA ADP

CISA assessment (SSVC): exploitation: none known, automatable: no

Show 2 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
SSVC assessment	removed	{"id":"CVE-2024-27834","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2024-05-16T04:00:11.988391Z"}	—
SSVC assessment	added	—	{"id":"CVE-2024-27834","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-11-04T17:36:46.499968Z"}

Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

04.11.2026Record modifiedApple

New references:

and 2 more references

Show 12 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://support.apple.com/en-us/120896
Reference	added	—	https://support.apple.com/en-us/120898
Reference	added	—	https://support.apple.com/en-us/120901
Reference	added	—	https://support.apple.com/en-us/120902
Reference	added	—	https://support.apple.com/en-us/120903
Reference	added	—	https://support.apple.com/en-us/120905
Reference	removed	https://support.apple.com/en-us/120896	—
Reference	removed	https://support.apple.com/en-us/120898	—
Reference	removed	https://support.apple.com/en-us/120901	—
Reference	removed	https://support.apple.com/en-us/120902	—
Reference	removed	https://support.apple.com/en-us/120903	—
Reference	removed	https://support.apple.com/en-us/120905	—

Source identifier: product-security@apple.com

04.11.2026Record modifiedCISA ADP

CVSS V3.1: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS V3.1: before AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H, after —

Weakness type: CWE-287

Show 5 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
CVSS	added	—	AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
CVSS	removed	AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H	—
Weakness type (CWE)	added	—	CWE-287
Weakness type (CWE)	removed	CWE-277	—
Affected versions (publisher)	added	—	Affected value removed. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2024/27xxx/CVE-2024-27834.json">CVE-2024-27834</a>

Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

Show one older change

04.11.2026Record modifiedCVE Program

New references:

and 8 more references

Show 47 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	http://seclists.org/fulldisclosure/2024/May/10
Reference	added	—	http://seclists.org/fulldisclosure/2024/May/12
Reference	added	—	http://seclists.org/fulldisclosure/2024/May/16
Reference	added	—	http://seclists.org/fulldisclosure/2024/May/17
Reference	added	—	http://seclists.org/fulldisclosure/2024/May/9
Reference	added	—	http://www.openwall.com/lists/oss-security/2024/05/21/1
Reference	added	—	https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ADCLQW54XN37VJZNYD3UKCYATJFIMYXG/
Reference	added	—	https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WKIXADCW3O4R2OOSDZGPU55XQFE6NA3M/
Reference	added	—	https://support.apple.com/en-us/HT214101
Reference	added	—	https://support.apple.com/en-us/HT214102
Reference	added	—	https://support.apple.com/en-us/HT214103
Reference	added	—	https://support.apple.com/en-us/HT214104
Reference	added	—	https://support.apple.com/en-us/HT214106
Reference	added	—	https://support.apple.com/kb/HT214100
Reference	added	—	https://support.apple.com/kb/HT214102
Reference	added	—	https://support.apple.com/kb/HT214104
Reference	added	—	https://support.apple.com/kb/HT214106
Reference	removed	http://seclists.org/fulldisclosure/2024/May/10	—
Reference	removed	http://seclists.org/fulldisclosure/2024/May/12	—
Reference	removed	http://seclists.org/fulldisclosure/2024/May/16	—
Reference	removed	http://seclists.org/fulldisclosure/2024/May/17	—
Reference	removed	http://seclists.org/fulldisclosure/2024/May/9	—
Reference	removed	http://www.openwall.com/lists/oss-security/2024/05/21/1	—
Reference	removed	https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ADCLQW54XN37VJZNYD3UKCYATJFIMYXG/	—
Reference	removed	https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WKIXADCW3O4R2OOSDZGPU55XQFE6NA3M/	—
Reference	removed	https://support.apple.com/en-us/HT214101	—
Reference	removed	https://support.apple.com/en-us/HT214102	—
Reference	removed	https://support.apple.com/en-us/HT214103	—
Reference	removed	https://support.apple.com/en-us/HT214104	—
Reference	removed	https://support.apple.com/en-us/HT214106	—
Reference	removed	https://support.apple.com/kb/HT214100	—
Reference	removed	https://support.apple.com/kb/HT214102	—
Reference	removed	https://support.apple.com/kb/HT214104	—
Reference	removed	https://support.apple.com/kb/HT214106	—
Reference type	removed	http://seclists.org/fulldisclosure/2024/May/10 Types: Mailing List	—
Reference type	removed	http://seclists.org/fulldisclosure/2024/May/12 Types: Mailing List	—
Reference type	removed	http://seclists.org/fulldisclosure/2024/May/16 Types: Mailing List	—
Reference type	removed	http://seclists.org/fulldisclosure/2024/May/17 Types: Mailing List	—
Reference type	removed	http://seclists.org/fulldisclosure/2024/May/9 Types: Mailing List	—
Reference type	removed	http://www.openwall.com/lists/oss-security/2024/05/21/1 Types: Mailing List	—
Reference type	removed	https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ADCLQW54XN37VJZNYD3UKCYATJFIMYXG/ Types: Mailing List	—
Reference type	removed	https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WKIXADCW3O4R2OOSDZGPU55XQFE6NA3M/ Types: Mailing List	—
Reference type	removed	https://support.apple.com/en-us/HT214101 Types: Vendor Advisory	—
Reference type	removed	https://support.apple.com/en-us/HT214102 Types: Vendor Advisory	—
Reference type	removed	https://support.apple.com/en-us/HT214103 Types: Vendor Advisory	—
Reference type	removed	https://support.apple.com/en-us/HT214104 Types: Vendor Advisory	—
Reference type	removed	https://support.apple.com/en-us/HT214106 Types: Vendor Advisory	—

Source identifier: af854a3a-2127-422b-91ae-364da2661108

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What is affected, what to do

Metrics

Response and mitigation

Prioritisation rationale

Immediate response (0-24 h)

Mitigation layers

Detection rules

Detection rules

Classification under NIS2 and CRA

Description

Affected products

Vendors and products

Affected operating systems

Weakness classes (CWE)

Public exploit references

References & sources

Changes to this CVE