Overview
CVE-2025-65083 details a security vulnerability discovered in GoSign Desktop, a software application for digital signatures. Specifically, versions up to and including 2.4.1 exhibit a weakness in TLS certificate validation when configured to utilize a proxy server. This flaw could potentially allow attackers to bypass integrity protection under specific and, admittedly, unusual circumstances involving untrusted proxy servers.
Technical Details
The core issue lies in the disabling of TLS certificate validation within GoSign Desktop when a proxy server is configured. While the application is designed assuming a secure proxy environment (e.g., within an enterprise network), the vulnerability arises if a user configures GoSign Desktop to use an arbitrary, potentially malicious proxy server. In such a scenario, where the proxy server does not properly validate HTTPS certificates from upstream servers, GoSign Desktop will also fail to do so, thus opening the door for man-in-the-middle (MitM) attacks. The security advisory highlights that this scenario is outside of the product’s designed use-cases.
It’s also important to note the security risk related to the ~/.gosign directory. Placing this directory in the home directory of an untrusted user and subsequently allowing other users to execute downloaded files from that location poses a significant security risk.
CVSS Analysis
The vulnerability has been assigned a CVSS score of 3.2, indicating a LOW severity. This is primarily due to the specific conditions required for exploitation. It hinges on a user intentionally configuring GoSign Desktop to use an untrusted proxy server, which is an unlikely scenario in typical enterprise deployments where proxies are managed and trusted.
- CVSS Score: 3.2
- Severity: LOW
Possible Impact
While the CVSS score is low, the potential impact should not be ignored. If exploited successfully, an attacker could potentially intercept and modify communications between GoSign Desktop and the target server. This could lead to:
- Data interception: Sensitive information exchanged between the application and the server could be compromised.
- Man-in-the-Middle attacks: An attacker could inject malicious data or code, potentially leading to remote code execution or other malicious activities.
However, the actual likelihood of this occurring is limited by the need for the user to intentionally configure the application to use a rogue proxy server.
Mitigation or Patch Steps
The recommended mitigation steps depend on the environment:
- Upgrade: Upgrade to a version of GoSign Desktop that addresses this vulnerability (if a patch is released). Check the vendor’s website for updates.
- Secure Proxy Configuration: Ensure that GoSign Desktop is configured to use a trusted proxy server that properly validates TLS certificates. This is the standard configuration in most enterprise environments.
- User Education: Educate users about the risks of using untrusted or unknown proxy servers.
- Secure File Handling: Ensure the
~/.gosigndirectory is secured and not placed in the home directory of untrusted users. Avoid executing downloaded files from untrusted sources.
