CVE-2015-0098 in Windows
Summary
by MITRE
Task Scheduler in Microsoft Windows 7 SP1 and Windows Server 2008 R2 SP1 allows local users to gain privileges by triggering application execution by an invalid task, aka "Task Scheduler Elevation of Privilege Vulnerability."
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Analysis
by VulDB Data Team • 12/02/2024
The Task Scheduler Elevation of Privilege Vulnerability identified as CVE-2015-0098 represents a critical security flaw in Microsoft Windows operating systems that affects Windows 7 SP1 and Windows Server 2008 R2 SP1 installations. This vulnerability resides within the Windows Task Scheduler component which is responsible for executing scheduled tasks and managing automated processes on the system. The flaw specifically manifests when the system processes tasks that have been corrupted or improperly configured, creating a scenario where malicious local users can exploit the system to escalate their privileges from standard user level to administrative privileges.
The technical exploitation of this vulnerability occurs through a specific mechanism involving invalid task execution within the Task Scheduler service. When a malicious user creates or modifies a scheduled task with improper parameters or corrupted task definitions, the Task Scheduler service fails to properly validate these task configurations before execution. This validation failure creates a privilege escalation path where the system attempts to execute the malformed task with elevated privileges, inadvertently granting the attacker the ability to run code with administrative rights. The vulnerability is classified as a privilege escalation issue under CWE-264, which specifically addresses permissions, privileges, and access controls. The underlying flaw stems from inadequate input validation and improper privilege handling within the Windows Task Scheduler service implementation.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a persistent foothold within the compromised system. Once successfully exploited, attackers can execute arbitrary code with elevated privileges, potentially leading to complete system compromise, data exfiltration, or establishment of backdoors. The vulnerability is particularly concerning because it requires minimal user interaction from the attacker, as local access is sufficient to trigger the exploit. This makes the vulnerability attractive to attackers who may have already gained initial access through other means such as phishing attacks or credential theft. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting the 'Exploitation for Privilege Escalation' tactic where adversaries leverage system weaknesses to gain higher-level permissions.
Mitigation strategies for CVE-2015-0098 should prioritize immediate patch deployment through Microsoft's security updates, as the vendor has released specific fixes for this vulnerability. System administrators should also implement restrictive access controls and monitoring of scheduled tasks to detect anomalous behavior. The principle of least privilege should be enforced by limiting user permissions and regularly auditing scheduled tasks through the Task Scheduler interface. Additional defensive measures include implementing application whitelisting policies to prevent unauthorized executable files from running, enabling Windows Defender Application Control, and monitoring for suspicious task creation activities. Organizations should also consider implementing network segmentation and regular security assessments to identify and remediate similar vulnerabilities in their infrastructure. The vulnerability highlights the importance of maintaining up-to-date systems and proper security hygiene practices to prevent exploitation of such critical flaws that can provide attackers with administrative access to entire systems.