CVSS 8.8 HIGH Bulletin: Apple Security Advisory HT213926 Published: 2023-09-21

CVE-2023-41991: Apple iOS & macOS Security Framework Certificate Validation Bypass (Predator Spyware)

Technical intelligence and weaponization dossier for CVE-2023-41991. Documented exploitation across 1 active malware families totaling 120 analyzed telemetry samples.

Attributed Families

Sample Volume

120

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Official NIST NVD

View NVD Record →

Vulnerability Specifications & Root Cause

Vulnerability ID	CVE-2023-41991
Common Name / Bulletin	Apple iOS & macOS Security Framework Certificate Validation Bypass (Predator Spyware) (`Apple Security Advisory HT213926`)
CWE Classification	`CWE-295: Improper Certificate Validation in Security.framework`
Affected Software & Versions	iOS before 16.7, iOS 17 before 17.0.1, macOS Ventura before 13.6, watchOS before 10.0.1
Technical Root Cause	Flaw in Apple Security.framework allowing malicious network actors or local applications to bypass code-signing certificate verification checks, chained in zero-click and one-click attack chains to deploy Intellexa Predator spyware.
Associated ATT&CK Techniques	`T1553.002` — Associated ATT&CK Technique `T1404` — Associated ATT&CK Technique `T1636` — Associated ATT&CK Technique

Malware Families Weaponizing CVE-2023-41991

Empirical catalog telemetry verifies that the following 1 malware families weaponize this vulnerability for initial access, privilege escalation, or lateral movement:

1 families

Malware Family	Category	Catalog Samples	Operational Profile
predator	Spyware	`120`	Predator is a premier commercial zero-day mercenary spyware platform engineered by Cytrox (part of the European surveillance consortium known as the Intellexa A...

Attributed Threat Actors & Syndicates

Threat intelligence confirms the following adversaries weaponize CVE-2023-41991 in enterprise intrusions and campaign toolkits:

Cytrox — Attributed Threat Group / Campaign Operator
Intellexa Alliance — Attributed Threat Group / Campaign Operator

SOC Detection & Threat Hunting Guidance

Threat hunting leads and behavioral telemetry patterns to identify weaponized exploitation of CVE-2023-41991 in enterprise networks:

macOS/iOS Unified Audit Logs showing sec_error_code certificate validation failures immediately followed by unexplained launches from /private/var/tmp.

Remediation & Defensive Hardening

SOC containment checklist and attack surface reduction measures to neutralize exploitation:

Actionable Guidance: Install iOS 16.7 / 17.0.1 and macOS 13.6 updates; enable iOS Lockdown Mode on devices assigned to high-risk executive or investigative personnel.

For end-to-end incident response procedures, consult our dedicated playbook: InfoStealer Protection & Remediation →

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