Description
A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software and Cisco Secure FTD Software could allow an unauthenticated, adjacent attacker to impersonate the peer device and obtain access at the level of the manager role, which is equivalent to root.
This vulnerability is due to improper management of the TLS certificate for the sftunnel management connection. An attacker could exploit this vulnerability by connecting to the sftunnel port using a crafted TLS certificate. A successful exploit could allow the attacker to become a registered sftunnel peer with root access.
Note: The attack is successful only if the sftunnel connection is down or the attack can disrupt the sftunnel connection long enough to execute the attack.
This vulnerability is due to improper management of the TLS certificate for the sftunnel management connection. An attacker could exploit this vulnerability by connecting to the sftunnel port using a crafted TLS certificate. A successful exploit could allow the attacker to become a registered sftunnel peer with root access.
Note: The attack is successful only if the sftunnel connection is down or the attack can disrupt the sftunnel connection long enough to execute the attack.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
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| Cisco | Cisco Secure Firewall Management Center (FMC) | unknown |
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| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | unknown |
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No data available yet.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
No advisories yet.
References
History
Wed, 16 Sep 2026 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software and Cisco Secure FTD Software could allow an unauthenticated, adjacent attacker to impersonate the peer device and obtain access at the level of the manager role, which is equivalent to root. This vulnerability is due to improper management of the TLS certificate for the sftunnel management connection. An attacker could exploit this vulnerability by connecting to the sftunnel port using a crafted TLS certificate. A successful exploit could allow the attacker to become a registered sftunnel peer with root access. Note: The attack is successful only if the sftunnel connection is down or the attack can disrupt the sftunnel connection long enough to execute the attack. | |
| Title | Cisco Secure Firewall Management Center and Secure Firewall Threat Defense Software sftunnel Unauthorized Authentication Bypass Vulnerability | |
| Weaknesses | CWE-295 | |
| References |
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| Metrics |
cvssV3_1
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Subscriptions
No data.
MITRE
Status: PUBLISHED
Assigner: cisco
Published:
Updated: 2026-09-16T20:15:35.850Z
Reserved: 2025-10-08T11:59:15.411Z
Link: CVE-2026-20323
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-16T21:17:10.313
Modified: 2026-09-16T21:17:10.313
Link: CVE-2026-20323
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
-
CWE-295
Improper Certificate Validation