Apple Multiple Products Improper Authentication
CVE-2024-27834 is a medium-severity improper authentication vulnerability in Safari from Apple, with a CVSS 3.1 base score of 5.5 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version 17.5 as the first without the flaw, so updating Safari to that release or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on November 4, 2026, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Safari to 17.5 or a later version.
- Update iOS and iPadOS to 16.7.8 or 17.5, whichever matches your release line, or a later version.
- Update macOS to 14.5 or a later version.
- CISA's required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
- Read the advisory on support.apple.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apple | Safari | before 17.5 | 17.5 |
| Apple | iOS and iPadOS | before 16.7.8; before 17.5 | 16.7.8, 17.5 |
| Apple | macOS | before 14.5 | 14.5 |
| Apple | tvOS | before 17.5 | 17.5 |
| Apple | watchOS | before 10.5 | 10.5 |
| Apple | iPadOS | before 16.7.8; 17.0 up to, but not including, 17.5 | 16.7.8, 17.5 |
| Apple | Iphone OS | before 16.7.8; 17.0 up to, but not including, 17.5 | 16.7.8, 17.5 |
| Webkitgtk | Webkitgtk | before 2.44.2 | 2.44.2 |
| Wpewebkit | Wpe Webkit | before 2.44.2 | 2.44.2 |
| Fedora Project | Fedora | 39; 40 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.5 | Medium | NVD |
| CVSS 3.1 | 5.5 | Medium | CISA (ADP) |
Official 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: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: partial).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Record last changed materially (score, affected products, status or references).
- Deadline for US federal agencies to remediate, set by CISA.
References
Advisories
- support.apple.com/en-us/120896Release Notes
- support.apple.com/en-us/120898Release Notes
- support.apple.com/en-us/120901Release Notes
- support.apple.com/en-us/120902Release Notes
- support.apple.com/en-us/120903Release Notes
- support.apple.com/en-us/120905Release Notes
- support.apple.com/en-us/HT214101Release Notes
- support.apple.com/en-us/HT214102Release Notes
- support.apple.com/en-us/HT214103Release Notes
- support.apple.com/en-us/HT214104Release Notes
- support.apple.com/en-us/HT214106Release Notes
- support.apple.com/kb/HT214100Release Notes
- support.apple.com/kb/HT214102Release Notes
- support.apple.com/kb/HT214104Release Notes
- support.apple.com/kb/HT214106Release Notes
Third-party and government advisories
- seclists.org/fulldisclosure/2024/May/10Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2024/May/12Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2024/May/16Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2024/May/17Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2024/May/9Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2024/05/21/1Mailing List, Third Party Advisory
- lists.fedoraproject.org/archives/list/[email protected]/message/ADCLQW54XN37VJZNYD3UKC…Mailing List, Third Party Advisory
- lists.fedoraproject.org/archives/list/[email protected]/message/WKIXADCW3O4R2OOSDZGPU5…Mailing List, Third Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-27834US Government Resource
- sekoia.com/blog/poisoned-source-apt29-watering-holes-targets-mobile-devices-with-n-day-exploitsThird Party Advisory
Other vulnerabilities in Safari
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 10.0 Critical severity
- 8.8 High severity
- 8.8 High severity
Recent Improper Authentication vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 8.8 High severity
- 8.8 High severity
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