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AUSCERT External Security Bulletin Redistribution
ESB-2021.1008
Advisory (icsa-20-082-01) Weintek EasyWeb cMT
24 March 2021
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AusCERT Security Bulletin Summary
---------------------------------
Product: Weintek EasyWeb cMT
Publisher: ICS-CERT
Operating System: Network Appliance
Impact/Access: Root Compromise -- Remote/Unauthenticated
Execute Arbitrary Code/Commands -- Remote/Unauthenticated
Cross-site Scripting -- Remote/Unauthenticated
Access Confidential Data -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2021-27446 CVE-2021-27444 CVE-2021-27442
Original Bulletin:
https://us-cert.cisa.gov/ics/advisories/icsa-20-082-01
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ICS Advisory (ICSA-21-082-01)
Weintek EasyWeb cMT
Original release date: March 23, 2021
Legal Notice
All information products included in https://us-cert.cisa.gov/ics are provided
"as is" for informational purposes only. The Department of Homeland Security
(DHS) does not provide any warranties of any kind regarding any information
contained within. DHS does not endorse any commercial product or service,
referenced in this product or otherwise. Further dissemination of this product
is governed by the Traffic Light Protocol (TLP) marking in the header. For more
information about TLP, see https://us-cert.cisa.gov/tlp/ .
1. EXECUTIVE SUMMARY
o CVSS v3 10.0
o ATTENTION: Exploitable remotely/low skill level to exploit
o Vendor: Weintek
o Equipment: cMT
o Vulnerabilities: Code Injection, Improper Access Control, Cross-site
Scripting
2. RISK EVALUATION
Successful exploitation of these vulnerabilities could allow an unauthenticated
remote attacker to access sensitive information and execute arbitrary code to
gain root privileges.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following models and OS versions of cMT are affected:
o cMT-SVR-1xx/2xx, versions prior to 20210305
o cMT-G01/G02, versions prior to 20210209
o cMT-G03/G04, versions prior to 20210222
o cMT3071/cMT3072/cMT3090/cMT3103/cMT3151, versions prior to 20210218
o cMT-HDM, versions prior to 20210204
o cMT-FHD, versions prior to 20210208
o cMT-CTRL01, versions prior to 20210302
3.2 VULNERABILITY OVERVIEW
3.2.1 IMPROPER CONTROL OF GENERATION OF CODE ('CODE INJECTION') CWE-94
The Weintek cMT product line is vulnerable to Code Injection, which may allow
an unauthenticated remote attacker to execute commands with root privileges on
the operation system.
CVE-2021-27446 has been assigned to this vulnerability. A CVSS v3 base score of
10.0 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:N/S:C/
C:H/I:H/A:H ).
3.2.2 IMPROPER ACCESS CONTROL CWE-284
The Weintek cMT product line is vulnerable to various improper access controls,
which may allow an unauthenticated attacker to remotely access and download
sensitive information and perform administrative actions on behalf of a
legitimate administrator.
CVE-2021-27444 has been assigned to this vulnerability. A CVSS v3 base score of
9.8 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:N/S:U/
C:H/I:H/A:H ).
3.2.3 IMPROPER NEUTRALIZATION OF INPUT DURING WEB PAGE GENERATION ('CROSS-SITE
SCRIPTING') CWE-79
The Weintek cMT product line is vulnerable to a cross-site scripting
vulnerability, which could allow an unauthenticated remote attacker to inject
malicious JavaScript code.
CVE-2021-27442 has been assigned to this vulnerability. A CVSS v3 base score of
9.4 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:N/S:U/
C:H/I:H/A:L ).
3.3 BACKGROUND
o CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities, Water and
Wastewater Systems
o COUNTRIES/AREAS DEPLOYED: Worldwide
o COMPANY HEADQUARTERS LOCATION: Taiwan
3.4 RESEARCHER
Marcin Dudek from CERT.PL reported these vulnerabilities to CISA.
4. MITIGATIONS
Weintek has released OS upgrades for the affected products . Refer to Weintek's
Technical Notice regarding these vulnerabilities.
CISA recommends users take defensive measures to minimize the risk of
exploitation of this vulnerability. Specifically, users should:
o Minimize network exposure for all control system devices and/or systems,
and ensure that they are not accessible from the Internet .
o Locate control system networks and remote devices behind firewalls, and
isolate them from the business network.
o When remote access is required, use secure methods, such as Virtual Private
Networks (VPNs), recognizing VPNs may have vulnerabilities and should be
updated to the most current version available. Also recognize VPN is only
as secure as the connected devices.
CISA reminds organizations to perform proper impact analysis and risk
assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices
on the ICS webpage on us-cert.cisa.gov . Several recommended practices are
available for reading and download, including Improving Industrial Control
Systems Cybersecurity with Defense-in-Depth Strategies .
Additional mitigation guidance and recommended practices are publicly available
on the ICS webpage on us-cert.cisa.gov in the Technical Information Paper,
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation
Strategies .
Organizations observing any suspected malicious activity should follow their
established internal procedures and report their findings to CISA for tracking
and correlation against other incidents.
No known public exploits specifically target these vulnerabilities.
For any questions related to this report, please contact the CISA at:
Email: CISAservicedesk@cisa.dhs.gov
Toll Free: 1-888-282-0870
CISA continuously strives to improve its products and services. You can help by
choosing one of the links below to provide feedback about this product.
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