CVE-2007-2404 in Mac OS X
Summary
by MITRE
CRLF injection vulnerability in CFNetwork on Apple Mac OS X 10.3.9 and 10.4.10 before 20070731 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via CRLF sequences in an unspecified context. NOTE: this can be leveraged for cross-site scripting (XSS) attacks.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 07/23/2019
The CVE-2007-2404 vulnerability represents a critical CRLF injection flaw within Apple's CFNetwork framework affecting Mac OS X versions 10.3.9 and 10.4.10 prior to the 20070731 security update. This vulnerability operates at the network layer where CRLF (Carriage Return Line Feed) sequences are improperly handled during HTTP header processing, creating a pathway for malicious actors to inject arbitrary HTTP headers into web responses. The flaw stems from insufficient input validation and sanitization mechanisms within the CFNetwork library, which serves as the core networking framework for Apple's operating system. When applications process user-supplied data through this vulnerable component, the CRLF sequences can be interpreted as header terminators rather than data, enabling attackers to manipulate HTTP responses in ways that were not intended by the application developers.
The technical exploitation of this vulnerability enables attackers to perform HTTP response splitting attacks, where malicious input containing CRLF sequences allows an attacker to inject additional HTTP headers into the response stream. This technique involves inserting characters like \r\n or %0d%0a into input fields that are then processed by the vulnerable CFNetwork component. The impact extends beyond simple header injection, as demonstrated by the note indicating this vulnerability can be leveraged for cross-site scripting attacks. This dual nature of exploitation occurs because the injected headers can redirect subsequent requests to malicious domains or inject script content into web pages, making the vulnerability particularly dangerous for web applications that rely on CFNetwork for HTTP communications. The vulnerability operates at a fundamental level where the networking stack fails to properly sanitize input before it reaches the application layer, creating a persistent security gap that affects any application using Apple's built-in networking libraries.
The operational impact of CVE-2007-2404 is substantial for organizations running affected Mac OS X versions, as it provides attackers with multiple attack vectors including session hijacking, cache poisoning, and data exfiltration. The vulnerability's exploitation can result in complete compromise of web application security models, as attackers can manipulate the HTTP response flow to redirect users to malicious sites or inject content that appears legitimate. This makes the vulnerability particularly dangerous in enterprise environments where Mac systems may be running web applications or acting as web servers. The attack surface is broad since CFNetwork is integrated into numerous Apple applications and services, making it difficult for administrators to identify all potentially vulnerable components. Additionally, the vulnerability's ability to enable XSS attacks means that even if direct HTTP response splitting is not the primary goal, the injected content can still result in unauthorized code execution within user browsers, leading to complete system compromise. This vulnerability aligns with CWE-113, which describes improper neutralization of CRLF characters in HTTP headers, and maps to ATT&CK technique T1566 for social engineering through malicious web content.
Organizations should implement immediate mitigations including applying the official Apple security updates released on 20070731, which addressed the underlying CRLF injection vulnerability in CFNetwork. System administrators should also implement network-level filtering to detect and block CRLF sequences in HTTP headers, particularly in applications that process user input. Application developers need to ensure proper input validation and sanitization of all data passed through CFNetwork components, implementing strict character filtering and encoding mechanisms. The vulnerability demonstrates the importance of proper security testing for networking libraries and highlights the need for input validation at multiple layers of application architecture. Security monitoring should include detection of anomalous HTTP header patterns that may indicate exploitation attempts, particularly in web applications running on Mac systems. Organizations should also consider implementing web application firewalls and content security policies to mitigate the XSS vector that can be leveraged through this vulnerability, as the primary exploitation method involves injecting malicious content into web responses that can execute in user browsers. The vulnerability serves as a reminder of the critical importance of keeping operating system components updated and the potential for seemingly minor networking flaws to create significant security breaches.