CVE-2020-9934

What is affected?

This vulnerability spans iOS, iPadOS, and macOS — Apple's mobile and desktop operating systems — covering the core platform that every app and user session on these devices depends on for enforcing boundaries between what different apps and users are permitted to see.

Overview

CVE-2020-9934 is an input validation vulnerability that allows a local attacker to view sensitive user information they should not have access to. Apple addressed it in the September 2020 release cycle (iOS 14.0, iPadOS 14.0, and macOS Catalina 10.15.7). Apple's own security advisories for this CVE are notably terse, providing only a high-level description without extensive technical detail — a common pattern for Apple advisories covering local information-disclosure issues.

Technical Details

The underlying flaw is an input validation weakness (consistent with the "unspecified" CWE classification here) that permits a process or user without the appropriate entitlement to access sensitive information that should be gated by the OS's privilege boundaries. The CVSS vector (AV:L/AC:L/PR:L/UI:N) indicates the attacker needs local access and some existing low-level privileges, but no user interaction and no unusual complexity — consistent with a straightforward access-control gap rather than a complex memory-corruption exploit chain.

Discovery

Addressed through Apple's routine security update process; Apple's advisories (HT211288 for iOS/iPadOS, HT211289 for macOS) document the fix without crediting an external researcher by name in the versions available.

Exploitation Context

CISA's KEV catalog listing, added roughly two years after the patch, confirms this vulnerability has been exploited in the wild. Local information-disclosure bugs of this kind are typically used by attackers who already have some code execution or access on a device — such as through a malicious app or a separate initial-access exploit — to harvest additional sensitive user data as part of a broader compromise, rather than as a standalone attack vector.

Remediation

1. Update to iOS 14.0, iPadOS 14.0, macOS Catalina 10.15.7, or later releases that contain the fix.
2. Enable automatic OS updates on managed device fleets to minimize the exposure window.
3. Review installed applications for anything untrusted or sideloaded, since exploitation of local information-disclosure bugs typically requires an existing local foothold.
4. For managed enterprise devices, ensure MDM policies enforce timely OS update compliance.
5. Treat any device that cannot be updated as an ongoing exposure given confirmed KEV exploitation.