CVE-2000-0927 in QuotaAdvisor
Summary
by MITRE
WQuinn QuotaAdvisor 4.1 does not properly record file sizes if they are stored in alternative data streams, which allows users to bypass quota restrictions.
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Analysis
by VulDB Data Team • 05/28/2018
The vulnerability identified as CVE-2000-0927 affects WQuinn QuotaAdvisor 4.1, a disk quota management tool designed to monitor and control file storage usage on Windows systems. This flaw represents a significant security weakness in how the software handles file size accounting, particularly when dealing with Windows file systems that support alternative data streams. The issue stems from the application's inability to accurately track file sizes when files are stored within alternative data streams, creating a scenario where users can manipulate their storage usage to evade imposed limits.
Alternative data streams in Windows are a feature that allows multiple data streams to be associated with a single file, with the primary stream containing the main file content while secondary streams can store additional metadata or data. The QuotaAdvisor 4.1 application fails to recognize that files stored in these alternative streams contribute to overall storage usage, effectively treating them as if they don't consume disk space. This misclassification occurs because the software's file size recording mechanism only examines the primary data stream and ignores the alternative streams where additional data may be stored, leading to incomplete accounting of actual disk space consumption.
The operational impact of this vulnerability is substantial as it allows malicious users or attackers to bypass quota restrictions that are typically implemented to prevent unauthorized storage consumption or to enforce fair usage policies. Users can store large amounts of data within alternative data streams while remaining under their assigned quota limits, potentially leading to unauthorized storage consumption that could impact system performance, storage availability for other users, or violate organizational policies. This vulnerability essentially creates a backdoor mechanism for users to exceed their allocated storage space without detection, undermining the fundamental purpose of disk quota management systems.
From a cybersecurity perspective, this vulnerability aligns with CWE-200, which covers information exposure, as it allows for unauthorized information access through manipulation of storage accounting mechanisms. The flaw also relates to CWE-119, memory vulnerability, since it involves improper handling of file data streams that could potentially lead to more complex exploitation scenarios. The vulnerability demonstrates a classic case of inadequate input validation and improper data handling in security-critical applications, where the software fails to account for all data components when performing resource tracking operations.
Organizations using WQuinn QuotaAdvisor 4.1 should immediately implement mitigations including upgrading to a newer version of the software that properly handles alternative data streams, implementing additional monitoring mechanisms to detect unusual storage patterns, and establishing more robust administrative controls over file system access. System administrators should also consider implementing additional security measures such as regular audit checks for files with alternative data streams and establishing clear policies regarding storage usage. The ATT&CK framework would categorize this vulnerability under privilege escalation techniques, as it allows users to effectively escalate their storage privileges beyond defined limits through manipulation of the quota enforcement mechanism, potentially leading to resource exhaustion or denial of service conditions for other legitimate users.