Cyber Resilience

CVE-2025-20378

Open Redirect in Splunk 9.2.0 – 9.2.9

Open Redirect
Published
12 November 2025
Modified
03 December 2025
Patch / advisory
View advisory
CVSS Score v3.1 3.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS Score 0.0024 15th percentile
Risk Priority 27 floored blend · peak EPSS

Summary

CVE-2025-20378 is a low-severity Open Redirect (CWE-601) vulnerability in Splunk Splunk. Its CVSS base score is 3.1 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Phishing (T1566); ranked at the 15th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

In Splunk Enterprise versions below 10.0.1, 9.4.5, 9.3.7, 9.2.9, and Splunk Cloud Platform versions below 10.0.2503.5, 9.3.2411.111, and 9.3.2408.121, an unauthenticated attacker could craft a malicious URL using the `return_to` parameter of the Splunk Web login endpoint. When an authenticated…

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user visits the malicious URL, it could cause an unvalidated redirect to an external malicious site. To be successful, the attacker has to trick the victim into initiating a request from their browser. The unauthenticated attacker should not be able to exploit the vulnerability at will.

CWE(s)
CWE-601

Related Threats

MITRE ATT&CK Enterprise Techniques

T1566 Phishing Initial Access
Adversaries may send phishing messages to gain access to victim systems.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-20382Same product: Splunk Splunk
CVE-2023-40595Same product: Splunk Splunk
CVE-2025-20322Same product: Splunk Splunk
CVE-2026-20259Same product: Splunk Splunk
CVE-2025-20226Same product: Splunk Splunk
CVE-2025-20384Same product: Splunk Splunk
CVE-2023-22935Same product: Splunk Splunk
CVE-2023-32709Same product: Splunk Splunk
CVE-2026-20144Same product: Splunk Splunk
CVE-2023-40598Same product: Splunk Splunk

Affected Assets

splunk
splunk
10.0.0 · 9.2.0 — 9.2.9 · 9.3.0 — 9.3.7 · 9.4.0 — 9.4.5
splunk
splunk cloud platform
9.3.2408 — 9.3.2408.121 · 9.3.2411 — 9.3.2411.111 · 10.0.2503 — 10.0.2503.5

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V3.7.2

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation directly checks and rejects untrusted redirect targets before they are used in a response.

AC-4 Information Flow Enforcement partial match

Information flow enforcement can restrict redirects to only approved/trusted destinations, stopping untrusted user-supplied URLs from being followed.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and untrusted-redirect controls that prevent CWE-601.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.23 Web filtering partial match
mitigates

Preventing access to attacker-controlled or malicious sites stops users from being redirected to untrusted locations via open-redirect or phishing links.

References