CVE-2015-7115 in iOS
Summary
by MITRE
libxml2 in Apple iOS before 9.2, OS X before 10.11.2, and tvOS before 9.1 allows remote attackers to obtain sensitive information or cause a denial of service (memory corruption) via a crafted XML document, a different vulnerability than CVE-2015-7116.
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Analysis
by VulDB Data Team • 11/16/2024
The vulnerability identified as CVE-2015-7115 represents a critical memory corruption issue within libxml2, the widely-used XML parsing library that forms the foundation of many Apple operating systems including iOS, macOS, and tvOS. This flaw exists in versions prior to the security updates released in iOS 9.2, macOS 10.11.2, and tvOS 9.1, exposing millions of devices to potential exploitation by remote attackers. The vulnerability stems from insufficient input validation and memory management within the XML parser's handling of malformed documents, creating a pathway for adversaries to manipulate memory structures and potentially extract sensitive information or disrupt system operations.
The technical nature of this vulnerability involves improper memory handling when processing crafted XML documents that contain maliciously constructed elements, attributes, or nested structures. When libxml2 attempts to parse such malformed inputs, the parser fails to properly validate memory allocations and deallocations, leading to memory corruption that can manifest in various ways including heap overflows, use-after-free conditions, or buffer overflows. The vulnerability operates at the parser level where XML documents are processed, making it particularly dangerous as it can be triggered through any application or service that utilizes libxml2 for XML processing, including web browsers, email clients, and system utilities.
The operational impact of CVE-2015-7115 extends beyond simple denial of service scenarios to include potential information disclosure and system compromise. Remote attackers can leverage this vulnerability to execute arbitrary code on affected systems, potentially gaining unauthorized access to sensitive data stored within the device memory. The memory corruption can be exploited to read or modify memory contents, potentially exposing system credentials, user data, or application secrets. Additionally, the vulnerability can be used to cause system crashes or reboots, creating persistent denial of service conditions that disrupt normal device operations and user productivity.
From a cybersecurity perspective, this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write vulnerabilities. The attack pattern follows typical exploitation techniques categorized under the MITRE ATT&CK framework, specifically targeting the "Exploitation for Privilege Escalation" and "Resource Hijacking" tactics. The vulnerability demonstrates the critical importance of input validation in security-critical libraries, as even seemingly benign XML parsing operations can become attack vectors when proper memory management protocols are not implemented. Organizations should prioritize immediate patching of affected systems and implement network monitoring to detect potential exploitation attempts targeting this specific memory corruption vulnerability in their deployed libxml2 implementations.