CVE-2025-65083 in GoSign Desktop
Summary
by MITRE • 11/17/2025
GoSign Desktop through 2.4.1 disables TLS certificate validation when configured to use a proxy server. This can be problematic if the GoSign Desktop user selects an arbitrary proxy server without consideration of whether outbound HTTPS connections from the proxy server to Internet servers succeed even for untrusted or invalid server certificates. In this scenario (which is outside of the product's design objectives), integrity protection could be bypassed. In typical cases of a proxy server for outbound HTTPS traffic from an enterprise, those connections would not succeed. (Admittedly, the usual expectation is that a client application is configured to trust an enterprise CA and does not set SSL_VERIFY_NONE.) Also, it is of course unsafe to place ~/.gosign in the home directory of an untrusted user and then have other users execute downloaded files.
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Analysis
by VulDB Data Team • 01/29/2026
The vulnerability identified as CVE-2025-65083 affects GoSign Desktop versions through 2.4.1 and represents a critical security flaw in the application's handling of TLS certificate validation when operating through proxy configurations. This issue stems from the software's design decision to disable TLS certificate validation specifically when a proxy server is configured, creating a significant attack surface that can be exploited by malicious actors. The flaw manifests when users configure arbitrary proxy servers without proper consideration of the security implications, particularly regarding outbound HTTPS connections to internet servers. This behavior violates fundamental security principles and creates a scenario where the application becomes vulnerable to man-in-the-middle attacks, as it willingly accepts invalid or untrusted certificates from proxy servers that may be compromised or malicious in nature.
The technical implementation of this vulnerability demonstrates a dangerous bypass of standard security protocols, where GoSign Desktop intentionally disables SSL/TLS verification mechanisms that are essential for maintaining secure communications. This behavior aligns with CWE-295, which addresses improper certificate validation, and represents a significant deviation from secure coding practices that should maintain certificate validation even in proxy scenarios. The vulnerability creates a trust boundary that can be easily exploited by attackers who control or compromise proxy servers, allowing them to intercept and potentially modify traffic between the client application and target servers. The impact extends beyond simple certificate validation issues, as it fundamentally undermines the integrity protection mechanisms that users expect from secure communication applications.
The operational impact of this vulnerability is severe, particularly in enterprise environments where users may inadvertently configure proxy settings that expose the application to malicious actors. When users select arbitrary proxy servers without proper security vetting, they create conditions where outbound HTTPS traffic can be intercepted and manipulated without detection. This scenario is especially dangerous because it operates outside the normal design objectives of the product, which would typically expect enterprise clients to be configured with proper trust relationships and certificate validation. The vulnerability becomes even more critical when considering that the application stores sensitive configuration data in the user's home directory, specifically in the ~/.gosign location, making it susceptible to privilege escalation attacks if untrusted users have access to the system. This situation creates a path for attackers to potentially gain unauthorized access to sensitive information or manipulate the application's behavior through malicious proxy configurations.
Mitigation strategies for this vulnerability must address both the immediate security concerns and the underlying architectural flaws that permit such behavior. Organizations should implement strict proxy server policies that require security validation before allowing any proxy configuration changes, ensuring that only trusted and verified proxy servers are used within the enterprise environment. The application should be modified to maintain TLS certificate validation even when proxy servers are configured, implementing proper certificate pinning or trust validation mechanisms that prevent the acceptance of invalid certificates. Additionally, system administrators should enforce strict access controls on user home directories and implement security measures such as file permissions, sandboxing, and privilege separation to prevent untrusted users from manipulating the application's configuration files. The solution should also include mandatory security awareness training for users to prevent them from selecting untrusted proxy servers and understanding the security implications of their configuration choices. This vulnerability highlights the critical importance of maintaining security controls even in complex network environments and demonstrates how seemingly minor configuration decisions can create significant security risks.