Norton Utilities Ultimate: Local Privilege Escalation to SYSTEM…

The ZDI-26-567 vulnerability in the NortonUtilitiesSvc service enables local privilege escalation to SYSTEM through a symlink attack. CVE-2024-13962 reveals the same TOCTTOU mechanism in Avast Cleanup Premium, though the discrepancy between products remains unexplained.

On August 13, 2026, Trend Micro published advisory ZDI-26-567 detailing a vulnerability in the NortonUtilitiesSvc service of Norton Utilities Ultimate. The flaw, tracked as CVE-2024-13962 with a CVSS score of 7.8, allows a local attacker to escalate privileges to SYSTEM by abusing a symbolic link. The disclosure comes roughly 22 months after the initial vendor report on October 11, 2024.

Key Takeaways

Vulnerability CVE-2024-13962 (CVSS 7.8) affects the NortonUtilitiesSvc service in Norton Utilities Ultimate with LPE impact to SYSTEM.
The attack exploits link following: a local attacker creates a symlink to manipulate service operations running with maximum privileges.
The CVE-2024-13962 record describes the identical mechanism in the context of Avast Cleanup Premium; ZDI sources are consistent on the Norton product, but the reason for the discrepancy is not clarified.
None of the sources explicitly confirm the availability of a patch or in-the-wild exploits at the time of publication.

The Mechanism: How the NortonUtilitiesSvc Service Relinquishes Control

The NortonUtilitiesSvc service operates with SYSTEM privileges and performs file system operations. According to the ZDI advisory, an attacker with the ability to execute code in a low-privileged context can create a symlink that the service follows during its operations.

The technique belongs to the TOCTTOU (time-of-check to time-of-use) race condition family. The service verifies the path of a file or directory, but between this verification and actual use, the attacker replaces the object with a symbolic link pointing to a sensitive system resource.

"By creating a symbolic link, an attacker can abuse the service to delete a directory. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM" — ZDI Advisory ZDI-26-567

The CVSS vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H confirms the local nature of the threat. Low attack complexity, no user interaction required, and high impact on confidentiality, integrity, and availability explain the HIGH (7.8) rating. Exploitation requires only limited local privileges.

The CVE Record and the Discrepancy with Avast Cleanup Premium

A distinctive element emerges from the CVE-2024-13962 record published on cve.org. The document describes the same vulnerability with the identical TOCTTOU/symlink mechanism, but in the context of Avast Cleanup Premium and its TuneupSvc service. The CVE is unique, the mechanism is identical, and both products belong to the Gen Digital portfolio.

The CVE-2024-13962 record describes the identical mechanism in the context of Avast Cleanup Premium; ZDI sources are consistent on the Norton product, but the reason for the discrepancy is not clarified. This overlap could indicate codebase sharing between the vendor's Windows optimization product lines. However, the source does not specify whether CVE-2024-13962 applies to both products due to actual shared libraries or for another reason. The hypothesis of a common codebase remains a plausible reading but is not textually confirmed by the available sources.

Timeline and Coordinated Disclosure

The researcher submitted the vulnerability to Trend Micro Zero Day Initiative on October 11, 2024. Coordinated disclosure occurred on August 13, 2026. This interval of roughly 22 months separates the initial report from the publication of technical details.

None of the available sources — neither the ZDI advisory nor the CVE record — explicitly confirms that a patch has been released or that updated versions of Norton Utilities Ultimate are protected. Advisory ZDI-26-567 provides no references to a specific update package.

The absence of official Norton release notes in the dossier prevents qualifying the remediation status. Users cannot independently verify whether their installation is vulnerable by comparing version numbers, as the sources do not provide them.

Recommended Actions

Check for the presence of Norton Utilities Ultimate on managed enterprise and consumer systems: the product targets the consumer segment but can be installed on corporate endpoints via personal licenses.
Monitor the official Norton support channel for any communications regarding the availability of specific updates for this vulnerability, given that the patch status is not documented in primary sources.
Apply the principle of least privilege for local user accounts, since the vulnerability requires a low-privileged code execution prerequisite but no initial administrative privileges.
Evaluate temporary removal of the product from critical endpoints until an update is confirmed, in the absence of patch information.
Review system logs for anomalous NortonUtilitiesSvc activity, particularly unsolicited directory deletion operations.

Risk Assessment and Operational Context

The vulnerability poses significant risk for Windows enterprise environments where Norton Utilities Ultimate is present. The CVSS 7.8 rates the threat as HIGH, but the local attack nature limits the surface compared to remote vulnerabilities. The low-privileged code execution prerequisite means the attacker must already have a foothold on the system.

This profile makes the vulnerability particularly relevant in post-compromise scenarios, where an attacker with standard user access seeks to elevate privileges for lateral movement or persistence. The SYSTEM context achieved grants total control over the machine, exposing data, configurations, and the ability to interfere with security solutions.

The 22-month window between report and disclosure suggests a prolonged coordination process, but offers no indication of the vendor's internal remediation status. The absence of confirmed in-the-wild exploits does not rule out the possibility of targeted use in focused attacks.

Verification Limits and Sources

Verification relies on advisory ZDI-26-567 as the primary structured source, corroborated by the official CVE record. The CVE record describes a different product (Avast Cleanup Premium) than the ZDI advisory (Norton Utilities Ultimate); this discrepancy is documented but not explained in the available sources. No information is available on in-the-wild exploits, released patches, or specific affected versions.

Sources

Information has been verified against cited sources and is current as of publication.

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Sources and references