CVE-2021-3422
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.
Does this matter?
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.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.60% probability · 48th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-125, CWE-20
- Affected
- splunk/splunk
- Source
- prodsec@splunk.com
EPSS 0.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://claroty.com/2022/03/24/blog-research-locking-down-splunk-enterprise-indexers-and-forwarders/Third Party Advisory
- https://www.splunk.com/en_us/product-security/announcements/svd-2022-0301.htmlVendor Advisory
- https://claroty.com/2022/03/24/blog-research-locking-down-splunk-enterprise-indexers-and-forwarders/Third Party Advisory
- https://www.splunk.com/en_us/product-security/announcements/svd-2022-0301.htmlVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.