{"id":"CVE-2021-20090","aliases":["EUVD-2021-7547","GHSA-6466-44wr-c6vv"],"status":"published","title":"A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version \u003c=...","description":"A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version \u003c= 1.02 and WSR-2533DHP3 firmware version \u003c= 1.24 could allow unauthenticated remote attackers to bypass authentication.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.99982,"percentile":0.99982,"model":"v2026.06.15"},"facts":{"in_kev":true,"known_exploited":true,"public_exploit":false,"fix_available":false},"cwes":["CWE-22"],"published":"2021-04-29T00:00:00Z","modified":"2026-06-17T03:33:15Z","kev":{"date_added":"2021-11-03","due_date":"2021-11-17","required_action":"Apply updates per vendor instructions.","known_ransomware_use":"Unknown"},"exploitation":[{"source":"euvd","since":"2021-11-03"},{"source":"kev","since":"2021-11-03"}],"exploits":[{"source":"nuclei","id":"CVE-2021-20090","title":"Buffalo WSR-2533DHPL2 - Path Traversal","type":"detection template","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-20090.yaml"}],"products":[{"vendor":"arcadyan","product":"buffalo firmware"},{"vendor":"buffalo","product":"wsr-2533dhp3-bk_firmware"},{"vendor":"buffalo","product":"wsr-2533dhpl2-bk_firmware"}],"references":[{"url":"https://www.tenable.com/security/research/tra-2021-13","tags":["x_transferred","Exploit","Third Party Advisory"]},{"url":"https://www.kb.cert.org/vuls/id/914124","tags":["third-party-advisory","x_transferred","Third Party Advisory","US Government Resource"]},{"url":"https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/","tags":["x_transferred","Exploit","Third Party Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20090","tags":["government-resource","US Government Resource"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-20090"},{"url":"https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation"},{"url":"https://github.com/advisories/GHSA-6466-44wr-c6vv"}],"sources":{"cve":[{"id":"CVE-2021-20090","description":"A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version \u003c= 1.02 and WSR-2533DHP3 firmware version \u003c= 1.24 could allow unauthenticated remote attackers to bypass authentication.","status":"published","published":"2021-04-29T00:00:00Z","modified":"2025-10-21T23:25:47.628Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"adp"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:32:55.564736Z"}],"euvd":[{"id":"EUVD-2021-7547","description":"A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version \u003c= 1.02 and WSR-2533DHP3 firmware version \u003c= 1.24 could allow unauthenticated remote attackers to bypass authentication.","status":"published","published":"2021-04-29T00:00:00Z","modified":"2025-10-21T23:25:47Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"exploited_since":"2021-11-03","updated_at":"2026-11-02T20:31:25.308373Z"}],"ghsa":[{"id":"GHSA-6466-44wr-c6vv","title":"A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version \u003c=...","description":"A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version \u003c= 1.02 and WSR-2533DHP3 firmware version \u003c= 1.24 could allow unauthenticated remote attackers to bypass authentication.","status":"published","published":"2022-05-24T17:49:10Z","modified":"2025-10-22T00:33:09Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:04:07.67458Z"}],"kev":[{"id":"CVE-2021-20090","title":"Arcadyan Buffalo Firmware Path Traversal Vulnerability","description":"Arcadyan Buffalo firmware contains a path traversal vulnerability that could allow unauthenticated, remote attackers to bypass authentication and access sensitive information. This vulnerability affects multiple routers across several different vendors.","cwes":["CWE-22"],"kev":{"date_added":"2021-11-03","due_date":"2021-11-17","required_action":"Apply updates per vendor instructions.","known_ransomware_use":"Unknown"},"updated_at":"2026-11-02T17:00:17.050017Z"}],"nvd":[{"id":"CVE-2021-20090","description":"A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version \u003c= 1.02 and WSR-2533DHP3 firmware version \u003c= 1.24 could allow unauthenticated remote attackers to bypass authentication.","status":"published","published":"2021-04-29T15:15:10.63Z","modified":"2026-06-17T03:33:15.487Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"secondary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:06:52.81233Z"}]}}