CVE-2021-3422

Indexer denial-of-service via malformed S2S request

HIGH
7.5
CVSS Score
Published: March 25, 2022 at 06:02 PM UTC
Updated: June 17, 2026 at 04:05 AM UTC
1 product affected across 1 vendorSplunk

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Severity
HIGH7.5
Exploit prediction
EPSS 0.6%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 7.3.9v < 8.0.9v < 8.1.3v < 8.2.08.0 ≤ v < 8.0.98.1 ≤ v < 8.1.3
Affected range stops below 7.3.9, so it looks safe — our inference, not a vendor statement
Affected range stops below 8.0.9, so it looks safe — our inference, not a vendor statement
Affected range stops below 8.1.3, so it looks safe — our inference, not a vendor statement
Affected range stops below 8.2.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

7.5HIGHSplunk
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125CWE-20

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