{"id":"CVE-2023-49105","published":"2023-11-21T22:15:08Z","modified":"2026-08-28T12:21:09Z","title":"ownCloud Improper Authentication Vulnerability","vendor":"ownCloud","product":"ownCloud","tier":"core","eol":null,"description":{"text":"An issue was discovered in ownCloud owncloud/core before 10.13.1. An attacker can access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured. This occurs because pre-signed URLs can be accepted even when no signing-key is configured for the owner of the files. The earliest affected version is 10.6.0.","provenance":"source","from":"NVD"},"summary":{"text":"The ownCloud core component (owncloud/core) before 10.13.1 contains an improper authentication flaw in its pre-signed URL handling, where URLs are accepted even when the file owner has no signing key configured. An attacker who knows a victim's username and whose target has no signing key configured can access, modify, or delete any of that victim's files over the network without authenticating or any user interaction.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:12:04Z"},"cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.4319,"percentile":0.98722,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2026-08-27","dueDate":"2026-08-30","ransomware":false,"requiredAction":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","notes":"https://owncloud.org/security ; https://owncloud.com/security-advisories/webdav-api-authentication-bypass-using-pre-signed-urls/ ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2023-49105","provenance":"source"},"vulncheckKev":{"dateAdded":"2026-08-26","exploitedFirstSeen":"2026-08-26","ransomware":false,"evidence":[{"url":"https://hunt.io/blog/chinese-speaking-operator-philippine-nuclear-naval-contractor","date":"2026-08-26"},{"url":"https://euvd.enisa.europa.eu/enisa/EUVD-2023-53114","date":"2026-08-27"},{"url":"https://previdian.com/CVE-2023-49105","date":"2026-08-27"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2026-08-27"},{"url":"https://www.recordedfuture.com/blog/august-2026-cve-landscape","date":"2026-09-08"}],"evidenceTotal":5,"provenance":"source"},"exploited":true,"otx":{"pulseCount":34,"pulses":[{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"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"}],"provenance":"machine"},"cwes":[{"id":"CWE-287","name":"Improper Authentication"}],"references":[{"url":"https://owncloud.com/security-advisories/webdav-api-authentication-bypass-using-pre-signed-urls/","tags":["Vendor Advisory"]},{"url":"https://owncloud.org/security","tags":["Product"]},{"url":"https://owncloud.com/security-advisories/webdav-api-authentication-bypass-using-pre-signed-urls/","tags":["Vendor Advisory"]},{"url":"https://owncloud.org/security","tags":["Product"]},{"url":"https://hunt.io/blog/chinese-speaking-operator-philippine-nuclear-naval-contractor","tags":["Third Party Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-49105","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: Unauthenticated web request via pre-signed URL exploits public app","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"An attacker can access, modify, or delete any file without authentication","start":66,"end":139}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1005","name":"Data from Local System","tactics":["collection"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Direct file read access from successful exploitation","mappingType":"primary_impact","evidence":[{"from":"description","quote":"can access, modify, or delete any file","start":78,"end":116}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1485","name":"Data Destruction","tactics":["impact"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Attacker deletes or modifies files directly","mappingType":"primary_impact","evidence":[{"from":"description","quote":"modify, or delete any file","start":90,"end":116}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2023-53114","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2023-53114","exploited":true,"exploitedSince":"2026-08-27","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":1,"skipped":0,"earliest":"2023-12-05","earliestUrl":"https://github.com/ambionics/owncloud-exploits","repos":[{"name":"ambionics/owncloud-exploits","url":"https://github.com/ambionics/owncloud-exploits","stars":41,"created":"2023-12-05"}]},"first":{"date":"2023-12-05","source":"PoC-in-GitHub","url":"https://github.com/ambionics/owncloud-exploits"},"provenance":"source"},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1005","T1485"],"provenance":"ai"}],"timeline":[{"date":"2023-11-21","kind":"published","label":"Published 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