{"id":"CVE-2021-26828","published":"2021-06-11T12:15:12Z","modified":"2026-06-17T03:43:49Z","title":"OpenPLC ScadaBR Unrestricted Upload of File with Dangerous Type 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 remote authenticated users to upload and execute arbitrary JSP files via view_edit.shtm.","provenance":"source","from":"NVD"},"summary":{"text":"OpenPLC ScadaBR, through 0.9.1 on Linux and through 1.12.4 on Windows, suffers from an unrestricted file upload flaw in its view_edit.shtm component, which fails to restrict the types of files that can be uploaded. An attacker with network access and valid low-privilege user credentials, requiring no user interaction, can upload and execute arbitrary JSP files on the server.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:10:32Z"},"cvss":{"score":8.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.39096,"percentile":0.98595,"date":"2026-10-31","provenance":"source"},"kev":{"dateAdded":"2025-12-03","dueDate":"2025-12-24","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/2174 ; https://nvd.nist.gov/vuln/detail/CVE-2021-26828","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":"2025-12-03"},{"url":"https://www.recordedfuture.com/blog/december-2025-cve-landscape","date":"2026-01-13"},{"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":5,"provenance":"source"},"exploited":true,"otx":null,"cwes":[{"id":"CWE-434","name":"Unrestricted Upload of File with Dangerous Type"}],"references":[{"url":"http://forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4","tags":["Broken Link","Exploit","Vendor Advisory"]},{"url":"http://packetstormsecurity.com/files/162564/ScadaBR-1.0-1.1CE-Linux-Shell-Upload.html","tags":["Exploit","Third Party Advisory"]},{"url":"https://youtu.be/k1teIStQr1A","tags":["Exploit","Third Party Advisory"]},{"url":"http://forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4","tags":["Broken Link","Exploit","Vendor Advisory"]},{"url":"http://packetstormsecurity.com/files/162564/ScadaBR-1.0-1.1CE-Linux-Shell-Upload.html","tags":["Exploit","Third Party Advisory"]},{"url":"https://youtu.be/k1teIStQr1A","tags":["Exploit","Third Party Advisory"]},{"url":"https://github.com/SCADA-LTS/Scada-LTS/pull/2174","tags":["Issue Tracking","Patch"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26828","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: remote exploitation of exposed web application","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"allows remote authenticated users to upload and execute arbitrary JSP files","start":69,"end":144}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: uploaded JSP files execute as server code","mappingType":"primary_impact","evidence":[{"from":"description","quote":"upload and execute arbitrary JSP files","start":106,"end":144}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2021-13613","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-13613","exploited":true,"exploitedSince":"2025-12-03","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":3,"skipped":0,"earliest":"2021-03-31","earliestUrl":"https://github.com/hev0x/CVE-2021-26828_ScadaBR_RCE","repos":[{"name":"hev0x/CVE-2021-26828_ScadaBR_RCE","url":"https://github.com/hev0x/CVE-2021-26828_ScadaBR_RCE","stars":9,"created":"2021-03-31"},{"name":"ridpath/CVE-2021-26828-Ultimate","url":"https://github.com/ridpath/CVE-2021-26828-Ultimate","stars":5,"created":"2025-05-30"},{"name":"h002733/CVE-2021-26828","url":"https://github.com/h002733/CVE-2021-26828","stars":0,"created":"2026-10-09"}]},"first":{"date":"2021-03-31","source":"PoC-in-GitHub","url":"https://github.com/hev0x/CVE-2021-26828_ScadaBR_RCE"},"provenance":"source"},"exploitRefs":["http://forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4","http://packetstormsecurity.com/files/162564/ScadaBR-1.0-1.1CE-Linux-Shell-Upload.html","https://youtu.be/k1teIStQr1A"],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1059"],"provenance":"ai"}],"timeline":[{"date":"2021-03-31","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub","url":"https://github.com/hev0x/CVE-2021-26828_ScadaBR_RCE","provenance":"source"},{"date":"2021-06-11","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26828","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":"2025-12-03","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2025-12-03","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-13613","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":"PoC-in-GitHub","daysToKev":1636},"priority":{"score":65.9,"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 388 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.72,"detail":"percentile 0.9859"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"3 NVD references tagged Exploit; 3 PoC-in-GitHub repos"},{"name":"Mentioned in OTX pulses","points":0.0,"detail":"0 pulses"},{"name":"CVSS severity","points":6.16,"detail":"base score 8.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}