CVE-2011-3441 in iOS
Summary
by MITRE
libinfo in Apple iOS before 5.0.1 does not properly formulate domain-name queries, which allows remote attackers to obtain sensitive information via a crafted DNS hostname.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 11/26/2021
The vulnerability identified as CVE-2011-3441 resides within the libinfo library component of Apple iOS versions prior to 5.0.1, representing a significant security flaw that affects the fundamental domain name resolution mechanisms within the operating system. This issue stems from improper handling of DNS hostname queries, creating a pathway for malicious actors to exploit the system's network resolution capabilities. The vulnerability operates at a foundational level within the iOS networking stack, specifically targeting how the system processes and formulates DNS queries when resolving domain names for network communication.
The technical implementation of this flaw involves the libinfo library's inadequate validation and construction of DNS query packets, particularly when processing specially crafted DNS hostnames. Attackers can manipulate the format of DNS queries to trigger unexpected behavior in the system's resolver, potentially leading to information disclosure through the retrieval of memory contents or system data that should remain confidential. This vulnerability falls under the category of information disclosure issues and aligns with CWE-200, which addresses the exposure of sensitive information through improper error handling or data processing. The flaw essentially allows an attacker to craft malicious DNS hostnames that, when processed by the vulnerable iOS system, can cause the system to reveal sensitive information through the DNS resolution process.
The operational impact of CVE-2011-3441 extends beyond simple information disclosure, as it creates opportunities for more sophisticated attacks that could compromise user privacy and system integrity. Remote attackers can leverage this vulnerability without requiring local access or authentication, making it particularly dangerous in mobile environments where iOS devices frequently connect to various networks. The implications affect all iOS devices running versions before 5.0.1, including iPhones, iPads, and iPod touches, potentially exposing users to targeted surveillance or data harvesting attacks. This vulnerability demonstrates the critical importance of proper input validation in system components that handle network communication and highlights how seemingly minor flaws in core libraries can have widespread consequences across entire operating system families.
Mitigation strategies for this vulnerability primarily involve updating to iOS version 5.0.1 or later, which includes patches that properly address the DNS query formulation issues within the libinfo library. Organizations and users should prioritize immediate deployment of the security update to protect against exploitation attempts. Additionally, network administrators should consider implementing DNS filtering and monitoring solutions to detect anomalous DNS query patterns that might indicate exploitation attempts. The ATT&CK framework categorizes this vulnerability under the T1071.004 technique for application layer protocol: DNS, where adversaries use DNS to communicate with command and control servers or exfiltrate data. Security professionals should also implement network segmentation and monitoring to detect unusual DNS traffic patterns that could indicate exploitation attempts, as the vulnerability specifically targets the DNS resolution process itself rather than network protocols or application layers.