CVE-2011-3447 in Mac OS X
Summary
by MITRE
CFNetwork in Apple Mac OS X 10.7.x before 10.7.3 does not properly construct request headers during parsing of URLs, which allows remote attackers to obtain sensitive information via a malformed URL.
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Analysis
by VulDB Data Team • 11/29/2021
The vulnerability identified as CVE-2011-3447 resides within Apple's CFNetwork framework, which serves as the core networking infrastructure for Mac OS X 10.7.x systems prior to version 10.7.3. This flaw manifests in the improper construction of HTTP request headers during URL parsing operations, creating a significant security gap that could be exploited by remote attackers to access sensitive information. The issue specifically affects the manner in which the system processes malformed URLs, leading to potential information disclosure through crafted network requests that manipulate header construction. This vulnerability represents a critical weakness in the operating system's network stack implementation, particularly impacting the security posture of systems running affected versions of Mac OS X.
The technical exploitation of this vulnerability occurs through manipulation of URL parsing mechanisms within CFNetwork, where malformed URLs trigger improper header construction during the request formation process. When the system encounters specially crafted URLs, the parsing logic fails to properly sanitize or validate the header components, potentially allowing attackers to inject or extract sensitive data through the compromised header construction. This flaw falls under the category of improper input validation and header manipulation, with direct implications for information disclosure and potential data interception. The vulnerability demonstrates a classic weakness in network protocol handling where insufficient validation of input parameters leads to unintended behavior in header generation, making it particularly dangerous in networked environments where URL parsing is frequent.
The operational impact of CVE-2011-3447 extends beyond simple information disclosure to potentially compromise the confidentiality of network communications on affected systems. Attackers could leverage this vulnerability to intercept or manipulate HTTP headers, potentially gaining access to authentication tokens, session identifiers, or other sensitive data that flows through the network stack. The vulnerability affects all applications and services that rely on CFNetwork for HTTP communication, including web browsers, email clients, and system utilities that make network requests. This broad impact means that a single compromised URL could potentially expose multiple applications to data leakage, making the vulnerability particularly concerning for enterprise environments where Mac OS X systems are prevalent and network traffic is extensive.
Mitigation strategies for CVE-2011-3447 primarily focus on applying the official security patch released by Apple for Mac OS X 10.7.3, which addresses the underlying URL parsing and header construction issues. System administrators should prioritize immediate deployment of the update to ensure all affected systems are protected against exploitation. Additionally, network monitoring solutions should be enhanced to detect anomalous URL patterns or header constructions that might indicate exploitation attempts. Organizations should implement network segmentation and access controls to limit exposure, while also conducting vulnerability assessments to identify any systems that may not have received the patch. The vulnerability aligns with CWE-20 Improper Input Validation and ATT&CK technique T1071.004 Application Layer Protocol: Web Protocols, emphasizing the need for robust input validation and protocol handling within network applications. Security teams should also consider implementing web application firewalls and intrusion detection systems to monitor for exploitation attempts targeting this specific vulnerability.