CVE-2025-20206: secure client Signature Bypass — Fix

Description

A vulnerability in the interprocess communication (IPC) channel of Cisco Secure Client for Windows could allow an authenticated, local attacker to perform a DLL hijacking attack on an affected device if the Secure Firewall Posture Engine, formerly HostScan, is installed on Cisco Secure Client. This vulnerability is due to insufficient validation of resources that are loaded by the application at run time. An attacker could exploit this vulnerability by sending a crafted IPC message to a specific Cisco Secure Client process. A successful exploit could allow the attacker to execute arbitrary code on the affected machine with SYSTEM privileges. To exploit this vulnerability, the attacker must have valid user credentials on the Windows system.

Is your site exposed to CVE-2025-20206?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Weakness Type (CWE)

CWE-347 CWE-347

Affected Products

Vendor	Product	Versions
cisco	secure_client	< 5.1.8.105
microsoft	windows	All

References

Advisories & Patches

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-secure-dll-injection-AOyzEqSg

Frequently Asked Questions

What is CVE-2025-20206? +

A vulnerability in the interprocess communication (IPC) channel of Cisco Secure Client for Windows could allow an authenticated, local attacker to perform a DLL hijacking attack on an affected device if the Secure Firewall Posture Engine, formerly HostScan, is installed on Cisco Secure Client. This vulnerability is due to insufficient validation of resources that are loaded by the application at run time. An attacker could exploit this vulnerability by sending a crafted IPC message to a specific Cisco Secure Client process. A successful exploit could allow the attacker to execute arbitrary code on the affected machine with SYSTEM privileges. To exploit this vulnerability, the attacker must have valid user credentials on the Windows system. It has a CVSS v3.1 base score of 7.1 (HIGH).

How severe is CVE-2025-20206? +

CVE-2025-20206 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-20206? +

CVE-2025-20206 affects products from cisco, microsoft, specifically: secure_client, windows. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-20206? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-22097

The firmware update mechanism does not include cryptographic signature validation. This allows anyone with access to the firmware update capability …

CVE-2026-46684

DataEase is an open source data visualization and analysis tool. Prior to 2.10.23, DataEase enterprise token handling can let TokenFilter#doFilter() …

CVE-2026-54733

The Microsoft 365 and Microsoft Entra ID Plugins for Moodle provide Office 365 and Azure Active Directory integration for Moodle. …

CVE-2026-44720

OpenLearnX is an open-source, decentralized learning and assessment platform. Prior to 2.0.4, a critical authentication vulnerability was identified in OpenLearnX …

CVE-2025-24800

Hyperbridge is a hyper-scalable coprocessor for verifiable, cross-chain interoperability. A critical vulnerability was discovered in the ismp-grandpa crate, that allowed …

CVE-2025-27498

aes-gcm is a pure Rust implementation of the AES-GCM. In decrypt_in_place_detached, the decrypted ciphertext (which is the correct ciphertext) is …

CVE-2025-20206