CVE-2024-27879: Apple iPadOS DoS Vulnerability

CVE-2024-27879 Overview

CVE-2024-27879 is an out-of-bounds memory access vulnerability affecting Apple iOS and iPadOS. The flaw stems from insufficient bounds checking in the affected platform components. A remote attacker can exploit this issue to cause unexpected application termination, resulting in a denial-of-service condition on the affected device.

Apple addressed the vulnerability by introducing improved bounds checks. Fixes are included in iOS 17.7, iPadOS 17.7, iOS 18, and iPadOS 18. The weakness is classified under [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer).

Critical Impact

A remote, unauthenticated attacker can trigger unexpected app termination on unpatched iOS and iPadOS devices, disrupting availability without requiring user interaction.

Affected Products

• Apple iOS versions prior to 17.7 and prior to 18
• Apple iPadOS versions prior to 17.7 and prior to 18
• Apple devices running vulnerable iOS/iPadOS builds

Discovery Timeline

• 2024-09-17 - CVE-2024-27879 published to the National Vulnerability Database (NVD)
• 2025-11-04 - Last updated in the NVD database

Technical Details for CVE-2024-27879

Vulnerability Analysis

The vulnerability is an out-of-bounds memory access condition in iOS and iPadOS. Apple's advisory describes the root issue as a missing bounds check that allowed memory operations to exceed buffer limits. When triggered, the affected process accesses memory outside the intended buffer and terminates unexpectedly.

The impact is limited to availability. The vulnerability does not expose data confidentiality or integrity, but it does interrupt application execution. Apple's fix introduces improved bounds checks to validate memory operations before they are performed.

The issue maps to [CWE-119], a class of memory safety defects common in C and Objective-C codebases used across Apple platforms. No public proof-of-concept code or exploit has been published, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Root Cause

The underlying defect is the absence of adequate boundary validation during a memory operation in iOS and iPadOS. Without bounds enforcement, crafted input can drive the affected code path to read or write outside its allocated buffer, causing the process to crash.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker delivers crafted input to a vulnerable component on the target device, triggering the out-of-bounds condition and causing the affected application to terminate. Refer to the Apple Support Document #121246 and Apple Support Document #121250 for vendor-confirmed technical context.

Detection Methods for CVE-2024-27879

Indicators of Compromise

• Unexpected and repeated termination of applications on iOS or iPadOS devices running versions earlier than 17.7 or 18
• Crash reports in device diagnostics referencing out-of-bounds memory access or buffer-related exceptions
• Anomalous network traffic preceding application crashes on managed mobile devices

Detection Strategies

• Inventory all iOS and iPadOS devices through mobile device management (MDM) and flag those running builds prior to 17.7 or 18
• Collect and review iOS crash logs from Settings > Privacy & Security > Analytics & Improvements for repeated application terminations
• Correlate device crash telemetry with network logs to identify potential exploitation attempts

Monitoring Recommendations

• Enable continuous OS version compliance monitoring through your MDM platform
• Forward mobile crash diagnostics to a centralized logging or SIEM platform for trend analysis
• Track Apple security advisories and bulletins to detect related follow-up CVEs in iOS and iPadOS

How to Mitigate CVE-2024-27879

Immediate Actions Required

• Update all iPhones to iOS 17.7 or iOS 18 (or later) without delay
• Update all iPads to iPadOS 17.7 or iPadOS 18 (or later) without delay
• Enforce minimum OS version policies through MDM to prevent vulnerable devices from accessing corporate resources
• Review Apple's advisories: Apple Support Document #121246 and Apple Support Document #121250

Patch Information

Apple resolved CVE-2024-27879 by adding improved bounds checks in iOS 17.7, iPadOS 17.7, iOS 18, and iPadOS 18. Apply the vendor-provided updates through Settings > General > Software Update. Additional details are available in the Full Disclosure mailing list post (Sep 32) and Full Disclosure mailing list post (Sep 39).

Workarounds

• No vendor-supplied workaround exists; apply the official iOS or iPadOS update
• Restrict device access to untrusted networks until patches are installed
• Use MDM conditional access policies to block non-compliant devices from sensitive applications

# Verify iOS/iPadOS version compliance from MDM (example pseudo-command)
mdm-cli query --field osVersion --filter "osVersion < 17.7"