CVE-2025-0065: Privilege Escalation Vulnerability in TeamViewer Clients for Windows Versions Prior to 15.62

The CVE-2025-0065 vulnerability, also known as the "Improper Neutralization of Argument Delimiters" vulnerability, affects the TeamViewer_service.exe component of TeamViewer clients for Windows systems with versions prior to 15.62. This security vulnerability enables an attacker with local unprivileged access to exploit arguments and ultimately elevate privileges on the targeted Windows system.

In this long-read post, we will explore the details of this vulnerability, provide sample code snippets to help illustrate the exploit, and reference original sources for further context.

Background on TeamViewer

TeamViewer is a popular remote access and desktop sharing tool used widely for remote tech support, virtual meetings, and online collaboration. The software connects and establishes remote desktop sessions between devices, allowing users to view and control each other's computers.

However, TeamViewer clients on Windows systems with versions prior to 15.62 have a security vulnerability in the TeamViewer_service.exe component that, when exploited, could allow an attacker with local unprivileged access to escalate privileges on the affected system.

Details of the Vulnerability

This vulnerability exists because of improper neutralization of argument delimiters that are passed along to the TeamViewer_service.exe component during service startup. An attacker with local unprivileged access can manipulate these arguments and execute arbitrary code with the privileges of the service account, which in this case, runs with SYSTEM-level privileges.

Exploit

To demonstrate how a potential exploit could work, below is a code snippet that abuses the vulnerability.

#include <windows.h>

int main(int argc, char *argv[]) {
  WCHAR szCmdLine[] = L"sc start TeamViewer_service param \"quoted -malicious_option\"";
  STARTUPINFOW si = {};
  PROCESS_INFORMATION pi = {};

  CreateProcessW(
    NULL,
    szCmdLine,
    NULL,
    NULL,
    FALSE,
    ,
    NULL,
    NULL,
    &si,
    &pi
  );

  WaitForSingleObject(pi.hProcess, INFINITE);
  CloseHandle(pi.hThread);
  CloseHandle(pi.hProcess);
  return ;
}

In this code snippet, the exploit uses the Windows sc start command to attempt to start the TeamViewer_service.exe with specially crafted arguments that include a malicious option. This exploits the improper neutralization of argument delimiters and results in the elevation of privileges on the system.

Original References

The vulnerability was first reported to TeamViewer and discussed in a security advisory on their website. The advisory details the vulnerability's background, affected products, and mitigation measures, as well as an acknowledgment of the researcher who reported it. Here are the important links to the original references:

1. TeamViewer Security Advisory: https://www.teamviewer.com/en/security/
2. CVE Information: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-0065

Mitigation and Solution

To protect against this vulnerability, it is essential to immediately upgrade TeamViewer clients for Windows to version 15.62 or later. This updated version has a patched TeamViewer_service.exe component that resolves the improper neutralization of argument delimiters.

Conclusion

The CVE-2025-0065 vulnerability is a serious security concern for users of TeamViewer clients for Windows systems with versions prior to 15.62. By exploiting this vulnerability, attackers with local unprivileged access can escalate their privileges and perform malicious actions.

Securing your systems from these types of threats involves understanding the potential risks and maintaining updated software. By upgrading to the latest version of TeamViewer and staying informed about security vulnerabilities, you can help safeguard your Windows systems against potential exploits.

Timeline

Published on: 01/28/2025 11:15:07 UTC