CVE-2025-20160
A vulnerability in the implementation of the TACACS+ protocol in Cisco IOS Software and Cisco IOS...
A vulnerability in the implementation of the TACACS+ protocol in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to view sensitive data or bypass authentication. This vulnerability exists because the system does not properly check whether the required TACACS+ shared secret is configured. A machine-in-the-middle attacker could exploit this vulnerability by intercepting and reading unencrypted TACACS+ messages or impersonating the TACACS+ server and falsely accepting arbitrary authentication requests. A successful exploit could allow the attacker to view sensitive information in a TACACS+ message or bypass authentication and gain access to the affected device.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.1
A vulnerability in the implementation of the TACACS+ protocol in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to view sensitive data or bypass authentication. This vulnerability exists because the system does not properly check whether the required TACACS+ shared secret is configured. A machine-in-the-middle attacker could exploit this vulnerability by intercepting and reading unencrypted TACACS+ messages or impersonating the TACACS+ server and falsely accepting arbitrary authentication requests. A successful exploit could allow the attacker to view sensitive information in a TACACS+ message or bypass authentication and gain access to the affected device.
- Record
CVE-2025-20160- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-287
- Updated
- 2026-11-02
EUVDEUVD-2025-31035
8.1
A vulnerability in the implementation of the TACACS+ protocol in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to view sensitive data or bypass authentication. This vulnerability exists because the system does not properly check whether the required TACACS+ shared secret is configured. A machine-in-the-middle attacker could exploit this vulnerability by intercepting and reading unencrypted TACACS+ messages or impersonating the TACACS+ server and falsely accepting arbitrary authentication requests. A successful exploit could allow the attacker to view sensitive information in a TACACS+ message or bypass authentication and gain access to the affected device.
- Record
EUVD-2025-31035- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-g4wr-69xr-36p6
8.1
A vulnerability in the implementation of the TACACS+ protocol in Cisco IOS Software and Cisco IOS...
A vulnerability in the implementation of the TACACS+ protocol in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to view sensitive data or bypass authentication.
This vulnerability exists because the system does not properly check whether the required TACACS+ shared secret is configured. A machine-in-the-middle attacker could exploit this vulnerability by intercepting and reading unencrypted TACACS+ messages or impersonating the TACACS+ server and falsely accepting arbitrary authentication requests. A successful exploit could allow the attacker to view sensitive information in a TACACS+ message or bypass authentication and gain access to the affected device.
- Record
GHSA-g4wr-69xr-36p6- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-287
- Updated
- 2026-11-02
NVD
8.1
A vulnerability in the implementation of the TACACS+ protocol in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to view sensitive data or bypass authentication. This vulnerability exists because the system does not properly check whether the required TACACS+ shared secret is configured. A machine-in-the-middle attacker could exploit this vulnerability by intercepting and reading unencrypted TACACS+ messages or impersonating the TACACS+ server and falsely accepting arbitrary authentication requests. A successful exploit could allow the attacker to view sensitive information in a TACACS+ message or bypass authentication and gain access to the affected device.
- Record
CVE-2025-20160- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-287
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-20160 is a high vulnerability (CVSS 8.1) in Cisco Ios Xe Software, published September 24, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.45%, the 39th percentile. No source names a fixed version.