{"id":"CVE-2021-3422","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-3422","generatedAt":"2026-10-28T00:31:51.476Z","title":"The lack of validation of a key-value field in the Splunk-to-Splunk protocol results in a denial-of-service in Splunk Enterprise instances configured to index Universal Forwarder traffic.","description":"The lack of validation of a key-value field in the Splunk-to-Splunk protocol results in a denial-of-service in Splunk Enterprise instances configured to index Universal Forwarder traffic. The vulnerability impacts Splunk Enterprise versions before 7.3.9, 8.0 versions before 8.0.9, and 8.1 versions before 8.1.3. It does not impact Universal Forwarders. When Splunk forwarding is secured using TLS or a Token, the attack requires compromising the certificate or token, or both. Implementation of either or both reduces the severity to Medium.","published":"2022-03-25T19:15:09.000Z","lastModified":"2026-06-17T04:05:04.000Z","status":"Modified","sourceIdentifier":"prodsec@splunk.com","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-125","CWE-20"],"affected":["splunk/splunk"],"epss":{"score":0.00601,"percentile":0.48469,"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":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.60%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://claroty.com/2022/03/24/blog-research-locking-down-splunk-enterprise-indexers-and-forwarders/","tags":["Third Party Advisory"],"source":"prodsec@splunk.com"},{"url":"https://www.splunk.com/en_us/product-security/announcements/svd-2022-0301.html","tags":["Vendor Advisory"],"source":"prodsec@splunk.com"},{"url":"https://claroty.com/2022/03/24/blog-research-locking-down-splunk-enterprise-indexers-and-forwarders/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.splunk.com/en_us/product-security/announcements/svd-2022-0301.html","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-3422","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."}