vulnerability new

CVE-2026-18717

● MEDIUM Confidence: 90% · Version 1

Executive summary

Public evidence documents CVE-2026-18717. This report does not assess any organization.

Technical analysis

View CSAF Summary Successful exploitation of these vulnerabilities could allow an attacker to read or write arbitrary local files, cause the application to issue outbound network requests, or intercept the connection to impersonate the trusted peer, complete the TLS handshake, and read or modify the protected communications. The following versions of Applied Systems Engineering ASE2000 V2 Communications Test Set are affected: ASE2000 >=2.25|<=2.37 (CVE-2018-1285, CVE-2026-18717) CVSS Vendor Equipment Vulnerabilities v3 9.8 Applied Systems Engineering Applied Systems Engineering ASE2000 V2 Communications Test Set Improper Restriction of XML External Entity Reference, Improper Certificate Validation Background Critical Infrastructure Sectors: Chemical, Critical Manufacturing, Energy, Water and Wastewater Countries/Areas Deployed: Worldwide Company Headquarters Location: United States Vulnerabilities Expand All + CVE-2018-1285 ASE2000 versions 2.25 through 2.37 is vulnerable to Apache log4net versions before 2.0.10 do not disable XML external entities when parsing log4net configuration files. This allows for XXE based attacks in applications that accept attacker controlled log4net configuration files. View CVE Details Affected Products Applied Systems Engineering ASE2000 V2 Communications Test Set Vendor: Applied Systems Engineering Product Version: Applied Systems Engineering ASE2000: >=2.25|<=2.37 Product Status: known_affected Remediations Mitigation ASE/Kalkitech provides an upgraded version 2.38 that fixes both vulnerabilities and customers are advised to upgrade to version 2.38. In version 2.38 the bundled log4net library is upgraded to version 3.3.1.0, and the IEC 60870-5-104 TLS client certificate validation logic is corrected to ensure proper validation of certificate error conditions. Vendor fix All customers running ASE2000 versions 2.25 through 2.37 are affected by this issue and are required to upgrade to version 2.38 or later to apply the security fix. Upgrade instructions and user documentation are available at www.ase-systems.com. For detailed, step-by-step guidance on upgrading to the latest version and patching the impacted components, please contact our support team at support@ase-systems.com. http://www.ase-systems.com Vendor fix All customers running ASE2000 versions 2.25 through 2.37 are affected by this issue and are required to upgrade to version 2.38 or later to apply the security fix. Upgrade instructions and user documentation are available at www.ase-systems.com. For detailed, step-by-step guidance on upgrading to the latest version and patching the impacted components, please contact our support team at support@ase-systems.com. mailto:support@ase-systems.com Mitigation Until the upgrade can be applied, the following interim measures reduce exposure: Vendor fix Restrict write access to the ASE2000 installation directory and its configuration files to trusted administrators only. Vendor fix Avoid using IEC 60870-5-104 over TLS across untrusted or shared networks; place ASE2000 hosts on an isolated, segmented network reachable only by intended peers. Mitigation Ensure the host is protected by a network firewall. Relevant CWE: CWE-611 Improper Restriction of XML External Entity Reference Metrics CVSS Version Base Score Base Severity Vector String 3.1 9.8 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 4.0 9.2 CRITICAL CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVE-2026-18717 ASE2000 2.35 through 2.37 is vulnerable to an improper certificate validation vulnerability, which may allow an attacker to impersonate the trusted peer, complete the TLS handshake, and read or modify protected communications. View CVE Details Affected Products Applied Systems Engineering ASE2000 V2 Communications Test Set Vendor: Applied Systems Engineering Product Version: Applied Systems Engineering ASE2000: >=2.25|<=2.37 Product Status: known_affected Remediations Mitigation ASE/Kalkitech provides an upgraded version 2.38 that fixes both vulnerabilities and customers are advised to upgrade to version 2.38. In version 2.38 the bundled log4net library is upgraded to version 3.3.1.0, and the IEC 60870-5-104 TLS client certificate validation logic is corrected to ensure proper validation of certificate error conditions. Vendor fix All customers running ASE2000 versions 2.25 through 2.37 are affected by this issue and are required to upgrade to version 2.38 or later to apply the security fix. Upgrade instructions and user documentation are available at www.ase-systems.com. For detailed, step-by-step guidance on upgrading to the latest version and patching the impacted components, please contact our support team at support@ase-systems.com. http://www.ase-systems.com Vendor fix All customers running ASE2000 versions 2.25 through 2.37 are affected by this issue and are required to upgrade to version 2.38 or later to apply the security fix. Upgrade instructions and user documentation are available at www.ase-systems.com. For detailed, step-by-step guidance on upgrading to the latest version and patching the impacted components, please contact our support team at support@ase-systems.com. mailto:support@ase-systems.com Mitigation Until the upgrade can be applied, the following interim measures reduce exposure: Vendor fix Restrict write access to the ASE2000 installation directory and its configuration files to trusted administrators only. Vendor fix Avoid using IEC 60870-5-104 over TLS across untrusted or shared networks; place ASE2000 hosts on an isolated, segmented network reachable only by intended peers. Mitigation Ensure the host is protected by a network firewall. Relevant CWE: CWE-295 Improper Certificate Validation Metrics CVSS Version Base Score Base Severity Vector String 3.1 7.4 HIGH CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N 4.0 9.1 CRITICAL CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N Acknowledgments Enoch Wang reported these vulnerabilities to CISA Legal Notice and Terms of Use This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy). Recommended Practices CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more 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 cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. CISA also recommends users take the following measures to protect themselves from social engineering attacks: Do not click web links or open attachments in unsolicited email messages. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time. Revision History Initial Release Date: 2026-08-27 Date Revision Summary 2026-08-27 1 Initial Publication Legal Notice and Terms of Use

Evidence and sources

Public evidence for CVE-2026-18717 with preserved provenance.

Authoritative Source Advisories

📄 CISA Cybersecurity Advisories ↗

Verified Evidence Claims

CVE-2026-18717 Applied Systems Engineering ASE2000 V2 Communications Test Set View CSAF Summary Successful exploitation of these vulnerabilities could allow an attacker to read or write arbitrary local files, cause the application to issue outbound network requests, or intercept the connection to impersonate the trusted peer, complete the TLS handshake, and read or modify the protected communications. The following versions of Applied Systems Engineering ASE2000 V2 Communications Test Set are affected: ASE2000 >=2.25|<=2.37 (CVE-2018-1285, CVE-2026-18717) CVSS Vendor Equipment Vulnerabilities v3 9.8 Applied Systems Engineering Applied Systems Engineering ASE2000 V2 Communications Test Set Improper Restriction of XML External Entity Reference, Improper Certificate Validation Background Critical Infrastructure Sectors: Chemical, Critical Manufacturing, Energy, Water and Wastewater Countries/Areas Deployed: Worldwide Company Headquarters Location: United States Vulnerabilities Expand All + CVE-2018-1285 ASE2000 versions 2.25 through 2.37 is vulnerable to Apache log4net versions before 2.0.10 do not disable XML external entities when parsing log4net configuration files. This allows for XXE based attacks in applications that accept attacker controlled log4net configuration files. View CVE Details Affected Products Applied Systems Engineering ASE2000 V2 Communications Test Set Vendor: Applied Systems Engineering Product Version: Applied Systems Engineering ASE2000: >=2.25|<=2.37 Product Status: known_affected Remediations Mitigation ASE/Kalkitech provides an upgraded version 2.38 that fixes both vulnerabilities and customers are advised to upgrade to version 2.38. In version 2.38 the bundled log4net library is upgraded to version 3.3.1.0, and the IEC 60870-5-104 TLS client certificate validation logic is corrected to ensure proper validation of certificate error conditions. Vendor fix All customers running ASE2000 versions 2.25 through 2.37 are affected by this issue and are required to upgrade to version 2.38 or later to apply the security fix. Upgrade instructions and user documentation are available at www.ase-systems.com. For detailed, step-by-step guidance on upgrading to the latest version and patching the impacted components, please contact our support team at support@ase-systems.com. http://www.ase-systems.com Vendor fix All customers running ASE2000 versions 2.25 through 2.37 are affected by this issue and are required to upgrade to version 2.38 or later to apply the security fix. Upgrade instructions and user documentation are available at www.ase-systems.com. For detailed, step-by-step guidance on upgrading to the latest version and patching the impacted components, please contact our support team at support@ase-systems.com. mailto:support@ase-systems.com Mitigation Until the upgrade can be applied, the following interim measures reduce exposure: Vendor fix Restrict write access to the ASE2000 installation directory and its configuration files to trusted administrators only. Vendor fix Avoid using IEC 60870-5-104 over TLS across untrusted or shared networks; place ASE2000 hosts on an isolated, segmented network reachable only by intended peers. Mitigation Ensure the host is protected by a network firewall. Relevant CWE: CWE-611 Improper Restriction of XML External Entity Reference Metrics CVSS Version Base Score Base Severity Vector String 3.1 9.8 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 4.0 9.2 CRITICAL CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVE-2026-18717 ASE2000 2.35 through 2.37 is vulnerable to an improper certificate validation vulnerability, which may allow an attacker to impersonate the trusted peer, complete the TLS handshake, and read or modify protected communications. View CVE Details Affected Products Applied Systems Engineering ASE2000 V2 Communications Test Set Vendor: Applied Systems Engineering Product Version: Applied Systems Engineering ASE2000: >=2.25|<=2.37 Product Status: known_affected Remediations Mitigation ASE/Kalkitech provides an upgraded version 2.38 that fixes both vulnerabilities and customers are advised to upgrade to version 2.38. In version 2.38 the bundled log4net library is upgraded to version 3.3.1.0, and the IEC 60870-5-104 TLS client certificate validation logic is corrected to ensure proper validation of certificate error conditions. Vendor fix All customers running ASE2000 versions 2.25 through 2.37 are affected by this issue and are required to upgrade to version 2.38 or later to apply the security fix. Upgrade instructions and user documentation are available at www.ase-systems.com. For detailed, step-by-step guidance on upgrading to the latest version and patching the impacted components, please contact our support team at support@ase-systems.com. http://www.ase-systems.com Vendor fix All customers running ASE2000 versions 2.25 through 2.37 are affected by this issue and are required to upgrade to version 2.38 or later to apply the security fix. Upgrade instructions and user documentation are available at www.ase-systems.com. For detailed, step-by-step guidance on upgrading to the latest version and patching the impacted components, please contact our support team at support@ase-systems.com. mailto:support@ase-systems.com Mitigation Until the upgrade can be applied, the following interim measures reduce exposure: Vendor fix Restrict write access to the ASE2000 installation directory and its configuration files to trusted administrators only. Vendor fix Avoid using IEC 60870-5-104 over TLS across untrusted or shared networks; place ASE2000 hosts on an isolated, segmented network reachable only by intended peers. Mitigation Ensure the host is protected by a network firewall. Relevant CWE: CWE-295 Improper Certificate Validation Metrics CVSS Version Base Score Base Severity Vector String 3.1 7.4 HIGH CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N 4.0 9.1 CRITICAL CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N Acknowledgments Enoch Wang reported these vulnerabilities to CISA Legal Notice and Terms of Use This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy). Recommended Practices CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more 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 cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. CISA also recommends users take the following measures to protect themselves from social engineering attacks: Do not click web links or open attachments in unsolicited email messages. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time. Revision History Initial Release Date: 2026-08-27 Date Revision Summary 2026-08-27 1 Initial Publication Legal Notice and Terms of Use

Attribution: CISA Cybersecurity Advisories

100% Confidence Analysis 🔍