An improper authentication and path traversal vulnerability exists in ASUSTOR Backup Plan and ASUSTOR EZ Sync.

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-18759
StatePUBLISHED
AssignerASUSTOR1
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-04 08:16:35 UTC
Updated2026-08-04 14:16:31 UTC
DescriptionThe background service of ABP or AES runs as NT AUTHORITY\SYSTEM and implements a file-based inter-process communication (IPC) mechanism protected by AES encryption. Because the encryption key file is readable by standard users and protected using DPAPI. Any authenticated local user can recover the key and forge valid IPC requests. Furthermore, the service does not check the identity of the requesting process and validates destination paths using an insufficient substring check. A local attacker can submit crafted encrypted requests containing directory traversal sequences to perform arbitrary file reads and arbitrary file writes as NT AUTHORITY\SYSTEM, leading to full local privilege escalation. Affected products and versions include: ABP (ASUSTOR Backup Plan) 2.0.7.10171 and earlier as well as AES (ASUSTOR EZSync) 1.1.1.3113 and earlier.

Risk And Classification

Primary CVSS: v4.0 8.5 HIGH from [email protected]

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.001160000 probability, percentile 0.018320000 (date 2026-08-07)

Problem Types: CWE-269 | CWE-287 | CWE-287 CWE-287 Improper Authentication | CWE-269 CWE-269 Improper Privilege Management

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary8.5HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS8.5HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Local
Attack Complexity
Low
Attack Requirements
None
Privileges Required
Low
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA ASUSTOR Inc. ABP affected ABP 2.0 2.0.7.10171 custom Windows, x86, 64 bit
CNA ASUSTOR Inc. AES affected AES 1.0 1.1.1.3113 custom Windows, x86, 64 bit

References

ReferenceSourceLinkTags
www.asustor.com/security/security_advisory_detail [email protected] www.asustor.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Kazuma Matsumoto, Security Researcher at GMO Cybersecurity by IERAE, Inc. (en)

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