Cyber Resilience

CVE-2020-13555

HighPublic PoC

Published: 17 February 2021

Published
17 February 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0006 17.6th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2020-13555 is a high-severity Incorrect Default Permissions (CWE-276) vulnerability in Advantech Webaccess\/Scada. Its CVSS base score is 8.8 (High).

Operationally, ranked at the 17.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

An exploitable local privilege elevation vulnerability exists in the file system permissions of Advantech WebAccess/SCADA 9.0.1 installation. In COM Server Application Privilege Escalation, an attacker can either replace binary or loaded modules to execute code with NT SYSTEM privilege.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

advantech
webaccess\/scada
9.0.1

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-276

Access control policy can specify and enforce secure default permissions for resources.

addresses: CWE-276

Guides setting of default permissions to the minimum required level.

addresses: CWE-276

Establishes requirements for appropriate default permissions on system resources as part of configuration management.

addresses: CWE-276

Baseline establishment and updates on install/upgrade ensure correct default permissions rather than insecure ones.

addresses: CWE-276

Requiring the most restrictive settings instead of defaults prevents incorrect default permissions on resources.

addresses: CWE-276

Requires documented processes that include setting and maintaining correct default permissions for configuration items.

addresses: CWE-276

Requires addressing secure default permissions in physical and environmental protection controls.

addresses: CWE-276

Tailoring explicitly overrides or scopes default permission assignments in the baseline to match the system's actual risk and operational needs.

References