{"schema":"threatline.record/2","record":{"id":"CVE-2021-40438","aliases":[],"summary":"Apache HTTP Server-Side Request Forgery (SSRF)","details":"A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.","categories":["Unclassified"],"product":"Apache","vendor":"Apache","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-40438","source_modified_at":"2026-08-06T03:55:20.326Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"Apache HTTP Server","vendor":"Apache Software Foundation","versions":[{"lessThanOrEqual":"2.4.48","status":"affected","version":"Apache HTTP Server 2.4","versionType":"custom"}],"defaultStatus":null}],"fixed_versions":[],"cvss":9,"severity":"Critical","kev":{"listed":true,"date_added":"2021-12-01","due_date":"2021-12-15","required_action":"Apply updates per vendor instructions.","ransomware_campaign_use":"Known"},"epss":{"probability":0.99999,"percentile":0.99997,"score_date":"2026-10-23"},"published_at":"2021-09-16T14:40:23.000Z","modified_at":"2026-08-06T03:55:20.326Z","provenance":[{"source":"CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23T17:00:09.9001Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2021-40438","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-08-06T03:55:20.326Z"},{"source":"Nuclei","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-40438.yaml","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":null},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-40438","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CISA KEV","CVE List","Nuclei","EPSS"],"references":[{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-40438","source":"CISA KEV"},{"source":"CVE List","url":"https://httpd.apache.org/security/vulnerabilities_24.html","tags":["x_refsource_MISC","x_transferred"]},{"source":"CVE 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