{"id":"CVE-2021-33197","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-33197","generatedAt":"2026-10-27T21:19:47.534Z","title":"In Go before 1.15.13 and 1.16.x before 1.16.5, some configurations of ReverseProxy (from net/http/httputil) result in a situation where an attacker is able to drop arbitrary headers.","description":"In Go before 1.15.13 and 1.16.x before 1.16.5, some configurations of ReverseProxy (from net/http/httputil) result in a situation where an attacker is able to drop arbitrary headers.","published":"2021-08-02T19:15:08.000Z","lastModified":"2026-06-17T03:54:20.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},"cwe":["CWE-862"],"affected":["golang/go"],"epss":{"score":0.0226,"percentile":0.82859,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (2.26%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://groups.google.com/g/golang-announce","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://groups.google.com/g/golang-announce/c/RgCMkAEQjSI","tags":["Exploit","Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://security.gentoo.org/glsa/202208-02","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://groups.google.com/g/golang-announce","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://groups.google.com/g/golang-announce/c/RgCMkAEQjSI","tags":["Exploit","Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202208-02","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-33197","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}