CVE-2025-20337 — Cisco Identity Services Engine Injection Vulnerability
A vulnerability in a specific API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to execute arbitrary code on the underlying operating system as root. The attacker does not require any valid credentials to exploit this vulnerability. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by submitting a crafted API request. A successful exploit could allow the attacker to obtain root privileges on an affected device.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Confirmed exploitation (CISA KEV)+35
- EPSS 68% (30-day exploitation probability)+15
- Technical severity (critical)+10
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
CISA required action CISA
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
US federal deadline: Aug 18, 2025 — passed 423 day(s) ago
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Cisco Cisco Identity Services Engine Software, Cisco Cisco ISE Passive Identity Connector, Cisco Identity Services Engine…).
- Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Cisco | Cisco Identity Services Engine Software |
version 3.3 Patch 6version 3.3 Patch 5version 3.4 Patch 1version 3.3 Patch 4version 3.4.0version 3.3 Patch 3version 3.3 Patch 1version 3.3 Patch 2 and 1 moreversion 3.3.0 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Cisco | Cisco ISE Passive Identity Connector | version 3.4.0version 3.3.0version 3.1.0version 3.2.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Cisco | Identity Services Engine |
version 3.3.0-patch1version 3.3.0version 3.3.0-patch2version 3.3.0-patch3version 3.3.0-patch4version 3.3.0-patch5version 3.3.0-patch6version 3.4.0 and 1 moreversion 3.4.0-patch1 |
Vulnerable | NIST National Vulnerability Database |
| Cisco | Identity Services Engine Passive Identity Connector |
version 3.3.0version 3.3.0-patch5version 3.3.0-patch1version 3.3.0-patch2version 3.3.0-patch3version 3.3.0-patch4version 3.4.0-patch1version 3.4.0 and 1 moreversion 3.3.0-patch6 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 10.0 | CVSS 3.1 | Critical | 3.9 | 6.0 | psirt@cisco.com via NIST National Vulnerability Database |
| 10.0 | CVSS 3.1 | Critical | — | — | GitHub, Inc. via GitHub Security Advisories |
| 10.0 | CVSS 3.1 | Critical | — | — | cisco via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H (score shown at the top: psirt@cisco.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CISA KEV details CISA
CISA lists a CVE once it has evidence of exploitation against real targets.
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.
EPSS over time FIRST
Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 68.00%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Look for parameters with command/query metacharacters and unexpected child processes of the service.
- Hunt retroactively in logs from before Jul 28, 2025 (KEV listing): exploitation may have started earlier.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · cisco/cisco identity services engine software, cisco/cisco ise passive identity connector
- SSVC assessment updated
- Record published
- Affected products added · cisco/identity services engine, cisco/identity services engine passive identity connector
- CVSS changed · 10.0
- Source status changed · → Analyzed
- Added to CISA KEV (detected)
- Record created in this database
- 2025
- Added to CISA KEV catalog
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 13, 2026 – Oct 13, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
4 on the record
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-76460 Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability KEV 28d
- High CVE-2026-20190 Cisco Identity Services Engine Information Disclosure Vulnerability Jun 17, 2026
- Critical CVE-2026-20181 Cisco Identity Services Engine Remote Code Execution Vulnerability Jun 17, 2026
- Medium CVE-2026-20195 Cisco Identity Services Engine Observable Response Discrepancy Vulnerability May 6, 2026
- Medium CVE-2026-20193 Cisco Identity Services Engine Authentication Bypass Vulnerability May 6, 2026
- Critical CVE-2026-20180 Cisco Identity Services Engine Multiple Remote Code Execution Vulnerability Apr 15, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2025-20337 is "Cisco Identity Services Engine Injection Vulnerability", rated Critical. It affects Cisco Identity Services Engine Software (Cisco); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 10.0 describes technical severity. EPSS 68.00% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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