{"schemaVersion":3,"id":"CVE-2023-45150","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"Nextcloud calendar is a calendar app for the Nextcloud server platform. Due to missing precondition checks the server was trying to validate strings of any length as email addresses even when megabytes of data were provided, eventually making the server busy and unresponsive. It is recommended that the Nextcloud Calendar app is upgraded to 4.4.4. The only workaround for users unable to upgrade is to disable the calendar app.","dates":{"published":"2023-10-16T19:06:03.674Z","modified":"2024-09-16T14:31:05.835Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":4.3,"severity":"medium","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":4.3,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":4.3,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00477,"percentile":0.3988,"severity":"low","asOf":"2026-10-20T00:00:00.000Z","change":{"pp":0.09099999999999998,"baselineDate":"2026-09-20T00:00:00.000Z","baselineScore":0.00386},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00477,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00477,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00477,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00477,"percentile":0.3988}],"last30":[{"date":"2026-09-20T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00386,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00477,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00477,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00477,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00477,"percentile":0.3988}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[{"id":"REF_E55CBFEF9E192D35","name":"Exploit Reference (hackerone.com)","source":"reference","url":"https://hackerone.com/reports/2058337","maturity":"unknown","reliabilityScore":0.2,"verified":false,"type":null,"platforms":[],"requiresAuth":null,"exploitdb":null,"metasploit":null}],"exploitCount":1,"weaknesses":[{"id":"CWE-400","name":"Uncontrolled Resource Consumption","description":"The product does not properly control the allocation and maintenance of a limited resource.","type":"weakness","status":"Draft","abstraction":"Class","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/400.html"},{"id":"CWE-354","name":"Improper Validation of Integrity Check Value","description":"The product does not validate or incorrectly validates the integrity check values or \"checksums\" of a message. This may prevent it from detecting if the data has been modified or corrupted in transmission.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":"Medium","url":"https://cwe.mitre.org/data/definitions/354.html"}],"affected":[{"vendor":"nextcloud","product":"calendar","name":"calendar","label":"calendar","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 1.0, < 4.4.4","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 1.0, < 4.4.4","eol":null,"hubHref":"/vendor/nextcloud/calendar"},{"vendor":"nextcloud","product":"security-advisories","name":"security-advisories","label":"security-advisories","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 1.0.0, < 4.4.4","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 1.0.0, < 4.4.4","eol":null,"hubHref":"/vendor/nextcloud/security-advisories"}],"affectedCount":2,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-r936-8gwm-w452","label":"github.com/nextcloud/security-advisories/security/advisories/GHSA-r936-8gwm-w452","hostname":"github.com","tags":["X Refsource CONFIRM","Vendor Advisory"]},{"url":"https://github.com/nextcloud/calendar/pull/5358","label":"github.com/nextcloud/calendar/pull/5358","hostname":"github.com","tags":["X Refsource MISC","Patch"]},{"url":"https://hackerone.com/reports/2058337","label":"hackerone.com/reports/2058337","hostname":"hackerone.com","tags":["X Refsource MISC","Exploit","Issue Tracking"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2023-10-16T19:06:03.674Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2024-09-16T14:31:05.835Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":27,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T19:32:13.237Z","stale":false,"partial":false}}