Rockwell Automation RSLinx
Summary
<p><a href="https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-167-02.json"><strong>View CSAF</strong></a></p> <h2>Summary</h2> <p><strong>Successful exploitation of this vulnerability can lead to a denial of service, where the application will become unresponsive and will not recover on its own.</strong></p> <p>The following versions of RSLinx Classic Third-Party Vulnerability are affected:</p> <ul> <li>RSLinx Classic <=4.50.00 (CVE-2020-13573)</li> </ul> <div class="csaf-table"> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>CVSS</th> <th>Vendor</th> <th>Equipment</th> <th>Vulnerabilities</th> </tr> </thead> <tbody> <tr> <td>v3 7.5</td> <td>Rockwell Automation</td> <td>RSLinx Classic Third-Party Vulnerability</td> <td>Out-of-bounds Read</td> </tr> </tbody> </table> </div> <h3>Background</h3> <ul> <li><strong>Critical Infrastructure Sectors: </strong>Critical Manufacturing, Energy, Food and Agriculture, Water and Wastewater</li> <li><strong>Countries/Areas Deployed: </strong>Worldwide</li> <li><strong>Company Headquarters Location: </strong>United States</li> </ul> <hr /> <h2>Vulnerabilities</h2> <div class="csaf-accordion"> <p><a class="csaf-accordion-toggle-all" href="https://www.cisa.gov/">Expand All +</a></p> <div class="csaf-accordion-item"> <h3><a class="csaf-accordion-toggle" href="https://www.cisa.gov/">CVE-2020-13573</a></h3> <div class="csaf-accordion-content"> <p>The affected product is vulnerable to a stack-based buffer overflow, which may allow an attacker to remotely execute arbitrary code.</p> <p><a href="https://www.cve.org/CVERecord?id=CVE-2020-13573">View CVE Details</a></p> <hr /> <h4>Affected Products</h4> <h5>RSLinx Classic Third-Party Vulnerability</h5> <div class="ics-vendor-version-status"> <div class="ics-vendor"><strong>Vendor:</strong><br />Rockwell Automation</div> <div class="ics-version"><strong>Product Version:</strong><br />Rockwell Automation RSLinx Classic: <=4.50.00</div> <div class="ics-status"><strong>Product Status:</strong><br />known_affected</div> </div> <div class="ics-remediations"> <h6>Remediations</h6> <p><strong>Mitigation</strong><br />Rockwell Automation recommends that customers using the affected software should upgrade to version 4.60.00 or later. Customers who are not able to upgrade to one of the corrected versions, should consider applying the available patch (BF31213) for their current version or applying the recommended security best practices.<br /><a href="https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1774.html">https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1774.html</a></p> </div> <p><strong>Relevant CWE:</strong> <a href="https://cwe.mitre.org/data/definitions/125.html">CWE-125 Out-of-bounds Read</a></p> <hr /> <h4>Metrics</h4> <div class="csaf-table csaf-metrics-table"> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>CVSS Version</th> <th>Base Score</th> <th>Base Severity</th> <th>Vector String</th> </tr> </thead> <tbody> <tr> <td>3.1</td> <td>7.5</td> <td>HIGH</td> <td><a href="https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H">CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H</a></td> </tr> <tr> <td>4.0</td> <td>8.7</td> <td>HIGH</td> <td><a href="https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N">CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N</a></td> </tr> </tbody> </table> </div> </div> </div> </div> <hr /> <h2>Acknowledgments</h2> <ul> <li>Rockwell Automation reported this vulnerability to CISA</li> </ul> <hr /> <h2>Legal Notice and Terms of Use</h2> <p>This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy).</p> <hr /> <h2>Recommended Practices</h2> <p>CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability.</p> <p>Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.</p> <p>Locate control system networks and remote devices behind firewalls and isolating them from business networks.</p> <p>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.</p> <p>CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.</p> <p>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.</p> <p>CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.</p> <p>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.</p> <p>Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.</p> <p>CISA also recommends users take the following measures to protect themselves from social engineering attacks:</p> <p>Do not click web links or open attachments in unsolicited email messages.</p> <p>Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.</p> <p>Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.</p> <p>No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time.</p> <hr /> <h2>Revision History</h2> <ul> <li><strong>Initial Release Date: </strong>2026-06-16</li> </ul> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>Date</th> <th>Revision</th> <th>Summary</th> </tr> </thead> <tbody> <tr> <td>2026-06-16</td> <td>1</td> <td>Initial Republication of Rockwell Automation Advisory SD1774</td> </tr> </tbody> </table> <hr /> <h2>Legal Notice and Terms of Use</h2>