{"id":"CVE-2021-26829","published":"2021-06-11T12:15:12Z","modified":"2026-06-17T03:43:50Z","title":"OpenPLC ScadaBR Cross-site Scripting Vulnerability","vendor":"OpenPLC","product":"ScadaBR","tier":"core","eol":null,"description":{"text":"OpenPLC ScadaBR through 0.9.1 on Linux and through 1.12.4 on Windows allows stored XSS via system_settings.shtm.","provenance":"source","from":"NVD"},"summary":{"text":"OpenPLC ScadaBR, the SCADA component that handles system settings via its system_settings.shtm page, contains a stored cross-site scripting flaw affecting the Linux builds through version 0.9.1 and the Windows builds through version 1.12.4. An attacker with network access and low-privileged credentials can plant malicious script in stored settings that executes in the browser of another user, such as an administrator, once they interact with the page.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-31T12:59:33Z"},"cvss":{"score":5.4,"severity":"MEDIUM","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","provenance":"source","from":"NVD"},"epss":{"score":0.4805,"percentile":0.98855,"date":"2026-10-30","provenance":"source"},"kev":{"dateAdded":"2025-11-28","dueDate":"2025-12-19","ransomware":false,"requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","notes":"This vulnerability could affect an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: https://github.com/SCADA-LTS/Scada-LTS/pull/3211 ; https://nvd.nist.gov/vuln/detail/CVE-2021-26829","provenance":"source"},"vulncheckKev":{"dateAdded":"2025-10-09","exploitedFirstSeen":"2025-10-09","ransomware":false,"evidence":[{"url":"https://www.forescout.com/blog/anatomy-of-a-hacktivist-attack-russian-aligned-group-targets-otics/","date":"2025-10-09"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2025-11-28"},{"url":"https://www.recordedfuture.com/blog/november-2025-cve-landscape","date":"2025-12-09"},{"url":"https://hs-21289959.f.hubspotemail.net/hubfs/21289959/Annual%20Threat%20Landscape%20Report_2025.pdf","date":"2026-01-19"},{"url":"https://www.loginsoft.com/reports/annually/vulnerability-intelligence-report-2025","date":"2026-01-20"},{"url":"https://www.forescout.com/resources/2025-threat-roundup/","date":"2026-01-29"}],"evidenceTotal":6,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"references":[{"url":"http://forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4","tags":["Vendor Advisory"]},{"url":"https://youtu.be/Xh6LPCiLMa8","tags":["Exploit","Third Party Advisory"]},{"url":"http://forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4","tags":["Vendor Advisory"]},{"url":"https://youtu.be/Xh6LPCiLMa8","tags":["Exploit","Third Party Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26829","tags":["US Government Resource"]},{"url":"https://www.forescout.com/blog/anatomy-of-a-hacktivist-attack-russian-aligned-group-targets-otics/","tags":["Third Party Advisory"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Exploited through public-facing web application input","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"allows stored XSS via system_settings.shtm","start":69,"end":111}],"model":"claude-haiku-5-5","confidence":"low","confidenceNote":"needs user interaction; not a public-facing exploit"},{"id":"T1059.007","name":"JavaScript","tactics":["execution"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Stored XSS yields JavaScript execution in browser","mappingType":"primary_impact","evidence":[{"from":"description","quote":"allows stored XSS via system_settings.shtm","start":69,"end":111}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2021-13614","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-13614","exploited":true,"exploitedSince":"2025-11-28","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":["https://youtu.be/Xh6LPCiLMa8"],"flow":[{"stage":"primary","techniques":["T1059.007"],"provenance":"ai"},{"stage":"related","techniques":["T1190"],"provenance":"ai","lowConfidence":true}],"timeline":[{"date":"2021-06-11","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26829","provenance":"source"},{"date":"2025-10-09","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://www.forescout.com/blog/anatomy-of-a-hacktivist-attack-russian-aligned-group-targets-otics/","provenance":"source"},{"date":"2025-11-28","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2025-11-28","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-13614","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":1631},"priority":{"score":66.6,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 387 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.77,"detail":"percentile 0.9886"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 NVD reference tagged Exploit"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":3.78,"detail":"base score 5.4"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}