CVE-2020-29619 in iCloud
Summary
by MITRE • 04/03/2021
An out-of-bounds read was addressed with improved input validation. This issue is fixed in tvOS 14.3, macOS Big Sur 11.1, Security Update 2020-001 Catalina, Security Update 2020-007 Mojave, iOS 14.3 and iPadOS 14.3, iCloud for Windows 12.0, watchOS 7.2. Processing a maliciously crafted image may lead to heap corruption.
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Analysis
by VulDB Data Team • 04/03/2021
This vulnerability represents a classic out-of-bounds read condition that was remediated through enhanced input validation mechanisms. The flaw manifests when processing specifically crafted image files that exceed expected parameter boundaries during memory allocation and data handling operations. The issue affects multiple Apple operating systems including tvOS 14.3, macOS Big Sur 11.1, and various security update versions for older systems, indicating a widespread impact across the Apple ecosystem. The vulnerability is categorized under CWE-129 as an insufficient input validation flaw that allows unauthorized access to memory regions beyond the intended buffer boundaries.
The technical exploitation of this vulnerability occurs during image processing operations where maliciously crafted image data triggers improper bounds checking during memory allocation. When the system attempts to read data beyond allocated buffer limits, it can access adjacent memory locations potentially containing sensitive information or corrupt heap structures. This heap corruption scenario creates opportunities for arbitrary code execution or system instability, as attackers can manipulate image metadata or binary content to force memory access violations that compromise system integrity.
The operational impact of this vulnerability extends across multiple platforms and applications within Apple's ecosystem, particularly affecting image processing components in iOS, iPadOS, macOS, watchOS, and iCloud for Windows. Attackers could potentially leverage this flaw through social engineering campaigns distributing malicious images via email attachments, messaging applications, or compromised websites. The vulnerability's exploitation potential aligns with ATT&CK technique T1203 by enabling adversaries to gain access to system memory and potentially escalate privileges through heap-based attacks.
Security mitigations for this vulnerability primarily involve applying the respective system updates that implement improved input validation controls and bounds checking mechanisms. Organizations should prioritize deployment of tvOS 14.3, macOS Big Sur 11.1, Security Update 2020-001 for Catalina, Security Update 2020-007 for Mojave, iOS 14.3, iPadOS 14.3, iCloud for Windows 12.0, and watchOS 7.2 releases. Additional protective measures include implementing image file validation policies, restricting image processing capabilities in untrusted environments, and monitoring for unusual memory access patterns that could indicate exploitation attempts. Network-based defenses should focus on inspecting image file headers and metadata to identify potentially malicious content before it reaches end-user systems.