{"api_version":"1","generated_at":"2026-07-14T13:26:12+00:00","cve":"CVE-2021-29474","urls":{"html":"https://cve.report/CVE-2021-29474","api":"https://cve.report/api/cve/CVE-2021-29474.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-29474","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-29474"},"summary":{"title":"CVE-2021-29474","description":"HedgeDoc (formerly known as CodiMD) is an open-source collaborative markdown editor. An attacker can read arbitrary `.md` files from the server's filesystem due to an improper input validation, which results in the ability to perform a relative path traversal. To verify if you are affected, you can try to open the following URL: `http://localhost:3000/..%2F..%2FREADME#` (replace `http://localhost:3000` with your instance's base-URL e.g. `https://demo.hedgedoc.org/..%2F..%2FREADME#`). If you see a README page being rendered, you run an affected version. The attack works due the fact that the internal router passes the url-encoded alias to the `noteController.showNote`-function. This function passes the input directly to findNote() utility function, that will pass it on the the parseNoteId()-function, that tries to make sense out of the noteId/alias and check if a note already exists and if so, if a corresponding file on disk was updated. If no note exists the note creation-function is called, which pass this unvalidated alias, with a `.md` appended, into a path.join()-function which is read from the filesystem in the follow up routine and provides the pre-filled content of the new note. This allows an attacker to not only read arbitrary `.md` files from the filesystem, but also observes changes to them. The usefulness of this attack can be considered limited, since mainly markdown files are use the file-ending `.md` and all markdown files contained in the hedgedoc project, like the README, are public anyway. If other protections such as a chroot or container or proper file permissions are in place, this attack's usefulness is rather limited. On a reverse-proxy level one can force a URL-decode, which will prevent this attack because the router will not accept such a path.","state":"PUBLIC","assigner":"security-advisories@github.com","published_at":"2021-04-26 22:15:00","updated_at":"2022-10-24 18:21:00"},"problem_types":["CWE-22"],"metrics":[],"references":[{"url":"https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-p528-555r-pf87","name":"https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-p528-555r-pf87","refsource":"CONFIRM","tags":[],"title":"Relative Path Traversal Attack on note creation · Advisory · hedgedoc/hedgedoc · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-29474","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-29474","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2021","cve_id":"29474","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"hedgedoc","cpe5":"hedgedoc","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"CVE_data_meta":{"ASSIGNER":"security-advisories@github.com","ID":"CVE-2021-29474","STATE":"PUBLIC","TITLE":"Relative Path Traversal Attack on note creation"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"hedgedoc","version":{"version_data":[{"version_value":"< 1.8.0"}]}}]},"vendor_name":"hedgedoc"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"HedgeDoc (formerly known as CodiMD) is an open-source collaborative markdown editor. An attacker can read arbitrary `.md` files from the server's filesystem due to an improper input validation, which results in the ability to perform a relative path traversal. To verify if you are affected, you can try to open the following URL: `http://localhost:3000/..%2F..%2FREADME#` (replace `http://localhost:3000` with your instance's base-URL e.g. `https://demo.hedgedoc.org/..%2F..%2FREADME#`). If you see a README page being rendered, you run an affected version. The attack works due the fact that the internal router passes the url-encoded alias to the `noteController.showNote`-function. This function passes the input directly to findNote() utility function, that will pass it on the the parseNoteId()-function, that tries to make sense out of the noteId/alias and check if a note already exists and if so, if a corresponding file on disk was updated. If no note exists the note creation-function is called, which pass this unvalidated alias, with a `.md` appended, into a path.join()-function which is read from the filesystem in the follow up routine and provides the pre-filled content of the new note. This allows an attacker to not only read arbitrary `.md` files from the filesystem, but also observes changes to them. The usefulness of this attack can be considered limited, since mainly markdown files are use the file-ending `.md` and all markdown files contained in the hedgedoc project, like the README, are public anyway. If other protections such as a chroot or container or proper file permissions are in place, this attack's usefulness is rather limited. On a reverse-proxy level one can force a URL-decode, which will prevent this attack because the router will not accept such a path."}]},"impact":{"cvss":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.7,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-20: Improper Input Validation "}]},{"description":[{"lang":"eng","value":"CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')"}]}]},"references":{"reference_data":[{"name":"https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-p528-555r-pf87","refsource":"CONFIRM","url":"https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-p528-555r-pf87"}]},"source":{"advisory":"GHSA-p528-555r-pf87","discovery":"UNKNOWN"}},"nvd":{"publishedDate":"2021-04-26 22:15:00","lastModifiedDate":"2022-10-24 18:21:00","problem_types":["CWE-22"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE","baseScore":5.8,"baseSeverity":"MEDIUM"},"exploitabilityScore":3.9,"impactScore":1.4},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:L/Au:N/C:P/I:N/A:N","accessVector":"NETWORK","accessComplexity":"LOW","authentication":"NONE","confidentialityImpact":"PARTIAL","integrityImpact":"NONE","availabilityImpact":"NONE","baseScore":5},"severity":"MEDIUM","exploitabilityScore":10,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:hedgedoc:hedgedoc:*:*:*:*:*:*:*:*","versionEndExcluding":"1.8.0","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"29474","Ordinal":"204678","Title":"CVE-2021-29474","CVE":"CVE-2021-29474","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"29474","Ordinal":"1","NoteData":"HedgeDoc (formerly known as CodiMD) is an open-source collaborative markdown editor. An attacker can read arbitrary `.md` files from the server's filesystem due to an improper input validation, which results in the ability to perform a relative path traversal. To verify if you are affected, you can try to open the following URL: `http://localhost:3000/..%2F..%2FREADME#` (replace `http://localhost:3000` with your instance's base-URL e.g. `https://demo.hedgedoc.org/..%2F..%2FREADME#`). If you see a README page being rendered, you run an affected version. The attack works due the fact that the internal router passes the url-encoded alias to the `noteController.showNote`-function. This function passes the input directly to findNote() utility function, that will pass it on the the parseNoteId()-function, that tries to make sense out of the noteId/alias and check if a note already exists and if so, if a corresponding file on disk was updated. If no note exists the note creation-function is called, which pass this unvalidated alias, with a `.md` appended, into a path.join()-function which is read from the filesystem in the follow up routine and provides the pre-filled content of the new note. This allows an attacker to not only read arbitrary `.md` files from the filesystem, but also observes changes to them. The usefulness of this attack can be considered limited, since mainly markdown files are use the file-ending `.md` and all markdown files contained in the hedgedoc project, like the README, are public anyway. If other protections such as a chroot or container or proper file permissions are in place, this attack's usefulness is rather limited. On a reverse-proxy level one can force a URL-decode, which will prevent this attack because the router will not accept such a path.","Type":"Description","Title":null},{"CveYear":"2021","CveId":"29474","Ordinal":"2","NoteData":"2021-04-26","Type":"Other","Title":"Published"},{"CveYear":"2021","CveId":"29474","Ordinal":"3","NoteData":"2021-04-26","Type":"Other","Title":"Modified"}]}}}