CVE-2017-6440 in libplist
Summary
by MITRE
The parse_data_node function in bplist.c in libimobiledevice libplist 1.12 allows local users to cause a denial of service (memory allocation error) via a crafted plist file.
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Analysis
by VulDB Data Team • 09/09/2020
The vulnerability identified as CVE-2017-6440 resides within the libimobiledevice libplist library version 1.12, specifically within the parse_data_node function located in the bplist.c file. This flaw represents a classic memory allocation error that can be exploited through maliciously crafted plist files, demonstrating a critical weakness in input validation and resource management within mobile device communication libraries. The issue affects systems that utilize libplist for parsing property list files, particularly those involved in mobile device synchronization and data exchange processes.
The technical implementation of this vulnerability stems from inadequate bounds checking and memory allocation handling within the binary plist parsing routine. When the parse_data_node function processes a malformed plist file, it fails to properly validate the size parameters or memory requirements before attempting allocation operations. This leads to scenarios where the application attempts to allocate excessive memory or encounters invalid size values that cause the memory allocator to fail, resulting in a denial of service condition. The vulnerability is classified as a memory allocation error, which aligns with CWE-770, indicating improper handling of resource allocation that can lead to system instability or complete service interruption.
From an operational perspective, this vulnerability poses significant risks to mobile device management systems and applications that rely on libplist for processing device configuration data. The local nature of the exploit means that an attacker must have access to the target system to craft and deliver the malicious plist file, but this access vector remains concerning given the potential for privilege escalation or system compromise through device synchronization processes. The denial of service impact can disrupt critical mobile device management workflows, affecting enterprise environments where device provisioning, configuration management, and data synchronization are essential operations.
The attack surface for this vulnerability extends to any system utilizing libimobiledevice libraries for plist file processing, particularly in enterprise mobile device management solutions, iOS device synchronization tools, and development environments working with iOS device data. Organizations implementing these technologies should consider the broader implications of such vulnerabilities within their mobile device management infrastructure, as they could potentially be leveraged as part of larger attack chains or used to disrupt business-critical operations involving mobile device provisioning and configuration management processes.
Mitigation strategies for CVE-2017-6440 should prioritize immediate patching of affected libplist library versions to address the memory allocation handling issues. System administrators should implement strict input validation measures for plist files processed by applications utilizing libimobiledevice libraries, including size limitations and format verification routines. Additionally, network segmentation and access controls should be enforced to limit local system access where possible, reducing the attack surface for local privilege escalation attempts. Security monitoring should include detection of anomalous memory allocation patterns and unusual plist file processing activities that could indicate exploitation attempts, aligning with ATT&CK technique T1489 for system network configuration modification and T1070 for indicator removal on host. Organizations should also consider implementing automated vulnerability scanning processes to identify systems running vulnerable versions of libplist and ensure comprehensive patch management across their mobile device ecosystems.