CVE-2007-0747 in Mac OS X
Summary
by MITRE
load_webdav in Apple Mac OS X 10.3.9 through 10.4.9 does not properly clean the environment when mounting a WebDAV filesystem, which allows local users to gain privileges by setting unspecified environment variables.
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Analysis
by VulDB Data Team • 06/14/2025
The vulnerability described in CVE-2007-0747 resides within the WebDAV filesystem mounting functionality of Apple Mac OS X versions 10.3.9 through 10.4.9. This issue represents a classic privilege escalation vulnerability that exploits improper environment variable handling during the WebDAV mounting process. The flaw occurs when the system fails to properly sanitize or clean the execution environment before mounting a WebDAV filesystem, creating a potential attack vector for local users to elevate their privileges. The vulnerability is particularly concerning because it leverages the inherent trust placed in system-level operations during filesystem mounting processes, where environment variables are typically expected to be properly isolated and managed. This weakness falls under the broader category of environment variable manipulation attacks that have been documented in various security frameworks including CWE-250, which specifically addresses execution with untrusted inputs and improper environment handling.
The technical exploitation of this vulnerability relies on local users manipulating unspecified environment variables that are not properly sanitized during the WebDAV mounting procedure. When a WebDAV filesystem is mounted, the system should isolate the execution context and clean any potentially malicious environment variables that could influence the mounting process. However, in affected versions of Mac OS X, this sanitization process fails, allowing attackers to inject malicious environment variables that can alter the behavior of the mounting process. The improper environment cleanup creates a scenario where a local user can craft specific environment variables that, when processed during the WebDAV mount operation, result in elevated privileges. This type of vulnerability is classified as a privilege escalation flaw under the ATT&CK framework, specifically mapping to privilege escalation techniques where adversaries leverage system-level operations to gain higher privileges than initially granted.
The operational impact of this vulnerability extends beyond simple local privilege escalation as it provides attackers with a mechanism to potentially gain root access or administrative privileges on affected systems. Since the vulnerability exists within a core system function used for mounting network filesystems, it could be exploited in various scenarios including when users mount WebDAV shares for legitimate purposes. The attack requires local access to the system, making it a local privilege escalation vulnerability rather than a remote one, but this still represents a significant security risk as local attackers could leverage this to gain elevated system access. The vulnerability affects a range of Mac OS X versions, indicating it was present for several years and likely exploited in various security incidents. Organizations running these affected versions would be at risk from both malicious insiders and attackers who gain local access to systems, as the privilege escalation could lead to complete system compromise.
Mitigation strategies for this vulnerability primarily focus on applying the official security patches released by Apple to address the environment variable sanitization issue in the WebDAV mounting process. System administrators should immediately upgrade affected Mac OS X systems to versions that contain the fix for this vulnerability, as the patch would properly implement environment variable cleaning during WebDAV operations. Additionally, organizations should implement monitoring for unusual WebDAV mounting activities and ensure that only trusted users have local access to systems. The vulnerability highlights the importance of proper input validation and environment sanitization in system-level operations, reinforcing principles from security standards like those outlined in the OWASP Top 10 and NIST guidelines for secure coding practices. Regular security assessments and vulnerability scanning should be conducted to identify similar environment variable handling issues in other system components, as this type of flaw can manifest in various forms across different software platforms and operating systems.