CVE Alert: CVE-2025-20371 – Splunk – Splunk Enterprise

Risk verdict

High risk vulnerability with potential to trigger a blind SSRF to call REST APIs on behalf of an authenticated high-privilege user; no active exploitation reported at present.

Why this matters

An attacker could abuse the SSRF to reach internal endpoints, potentially exposing, modifying or deleting sensitive data accessed via REST APIs. If leveraged against admin accounts, the impact could extend to monitoring configurations, data sources, and policy settings, impairing security posture and operations.

Most likely attack path

An attacker would need to entice a logged-in, high-privilege user to perform an action that causes the server to fetch an attacker-specified URL (SSRF). The fault allows remote-triggered requests over the network, but requires user interaction and no privileges, so the initial access relies on social engineering or phishing combined with high-privilege session context to reach sensitive APIs.

Who is most exposed

Institutions running on-prem Splunk Enterprise or Splunk Cloud with older patch levels and exposed management interfaces are most at risk. Deployments with highly privileged accounts and internet-accessible consoles are particularly relevant.

Detection ideas

• Unusual outbound requests from the Splunk host to non-canonical destinations
• REST API activity from authenticated high-privilege users to internal endpoints
• VoIP-like bursts of API calls shortly after user-driven actions
• Anomalous URL or hostnames appearing in API request logs
• Patterned success responses for invalid or unexpected URLs

Mitigation and prioritisation

• Patch to affected build lines: 10.0.1+, 9.4.4+, 9.3.6+, 9.2.8+ (and corresponding cloud patch levels)
• Enforce network egress controls and restrict internal REST API access
• Deploy web/app layer controls to validate outbound requests and block SSRF patterns
• Implement stricter access for admin accounts; enable MFA and session monitoring
• Change-management: plan staged rollout, test compatibility, verify API and dashboard integrity post-patch

Note: treat as priority 1 if an EPSS or KEV indicator appears in updates; otherwise proceed with standard urgent remediation.