CVE-2026-92253 in WatchDog
Summary
by MITRE • 09/20/2026
Improper link resolution before file access in the quarantine restoration process of WatchDog Anti-Virus 1.8.640 on Windows allows local, low-privileged attackers to cause a quarantined file to be written to an arbitrary filesystem location by creating a directory junction at the original file path and persuading an administrator to restore the file. This may enable modification of protected files or SYSTEM-level code execution through DLL hijacking.
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Analysis
by VulDB Data Team • 09/20/2026
The vulnerability identified in WatchDog Anti-Virus version 1.8.640 for Windows represents a critical flaw within the quarantine restoration mechanism, specifically stemming from improper link resolution prior to file access operations. This security defect allows local attackers with low privileges to manipulate the filesystem structure during the process of restoring files that have been previously quarantined by the antivirus software. The core technical issue lies in how the application handles symbolic links and directory junctions when determining the destination path for a restored file. Instead of validating or sanitizing these paths against potential redirection attacks, the software proceeds with the restoration operation based on potentially maliciously crafted filesystem metadata created by an attacker.
The operational mechanism of this exploitation involves several precise steps executed by a low-privileged user. First, the attacker creates a directory junction at the original file path where the quarantined item was located before being moved to quarantine storage. This junction acts as a pointer that redirects any access intended for that specific location to an arbitrary target directory chosen by the attacker. Subsequently, the attacker must persuade or trick a privileged user, typically an administrator with higher system rights, into initiating the restoration of the quarantined file through the WatchDog Anti-Virus interface. When this action is performed, the antivirus software resolves the path using the junction created earlier rather than writing directly to the intended safe location. Consequently, the content of the restored file is written to the arbitrary filesystem location specified by the attacker's junction target.
The impact of this vulnerability extends beyond simple unauthorized file placement and poses significant risks to system integrity and confidentiality. By controlling where a quarantined file is written, an attacker can overwrite protected system files or configuration data that are normally inaccessible due to strict access control lists. More critically, if the restored item is a dynamic link library (DLL), this flaw enables DLL hijacking attacks. When the operating system loads the compromised DLL from the arbitrary location instead of the legitimate one, it executes code under the context of the process performing the restoration or subsequent applications that load the DLL. If these processes run with elevated privileges, such as during administrative tasks or scheduled scans, this can lead to SYSTEM-level code execution, granting the attacker complete control over the affected machine.
This vulnerability aligns closely with Common Weakness Enumeration (CWE) standards, specifically CWE-59: Improper Link Resolution Before File Access, also known as a Time-of-check to Time-of-use (TOCTOU) race condition variant involving symbolic links. It is further categorized under CWE-22: Improper Limitation of a Pathname to a Restricted Directory if the resolution fails to restrict output to expected directories. From an offensive security perspective, this technique corresponds to ATT&CK tactic T1564.003, which covers Hidden Files and Directories via NTFS Junctions or Symbolic Links, and potentially T1218: Signed Binary Proxy Execution if leveraged for DLL hijacking scenarios. The attack vector is classified as Local (L) with Low Privileges required (L), indicating that while initial access requires local presence, the elevation of privilege occurs through the exploitation of trust relationships within the antivirus software's administrative functions.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. The primary defense is to apply vendor-provided patches or updates immediately if available, as this specific version has been identified with the flaw. Administrators should be educated on the risks associated with restoring files from quarantine without verifying their integrity and origin, ensuring that only trusted items are restored by privileged accounts. From a technical standpoint, antivirus software vendors must implement strict path validation checks before performing file write operations during restoration processes. This includes resolving all symbolic links and junctions to their physical paths and validating that the final destination resides within an allowed directory structure. Additionally, implementing integrity verification mechanisms such as digital signatures for quarantined files can prevent attackers from substituting malicious payloads into the quarantine store in the first place.