# CVE-2025-66835: TrueConf Client DLL hijacking in wfapi.dll

Source: https://junglewise.ai/threats/cve-2025-66835-trueconf-client-dll-hijacking-in-wfapi-dll  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-12-30. Updated: 2026-07-05  
License: CC BY 4.0 with a link back

CVE-2025-66835 · Severity: high · CVSS 7.1 · Published 2025-12-30

TrueConf Client, a video conferencing and collaboration application, is vulnerable to a security flaw that allows a local attacker to run unauthorized software on a user's computer. By placing a malicious file in specific folders on the system, an attacker can trick the application into executing their code whenever the program starts. This could lead to the theft of personal data, unauthorized access to communications, or a permanent foothold on the infected machine.

Technologies: [TrueConf Client](https://junglewise.ai/threats/technologies/client). Vendors: [Trueconf](https://junglewise.ai/threats/vendors/trueconf).

## Quick answers

**Is CVE-2025-66835 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-66835 being exploited in the wild.

**How severe is CVE-2025-66835?** High severity, with a CVSS score of 7.1, published 30 December 2025.

**Which products and versions are affected?** TrueConf Client 8.5.2.

**Is there a fix for CVE-2025-66835?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2025-66835 attacked?** It is attacked with local access, in a network appliance.

**Am I affected by CVE-2025-66835?** Check whether you run Trueconf or TrueConf Client at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

TrueConf Client 8.5.2 is vulnerable to DLL hijacking (CWE-427) because it attempts to load the library 'wfapi.dll' without specifying an absolute file path. This allows a local, low-privileged attacker to exploit the Windows DLL search order by placing a malicious version of the DLL in a user-writable directory included in the system PATH, such as the WindowsApps folder in the user's AppData directory. When the TrueConf.exe process starts, it loads the attacker's DLL instead of the intended system file, resulting in arbitrary code execution and potential persistence within the context of the logged-in user. The vulnerability was confirmed on Windows 10 22H2. Mitigation involves using absolute paths for library loading and implementing secure DLL search flags via SetDefaultDllDirectories.

## Affected products

- TrueConf TrueConf Client 8.5.2

## Timeline

- 2025-11-23: disclosed: Vulnerability discovered by Morteza Maleki
- 2025-12-30: advisory: CVE-2025-66835 published

## References

- [https://github.com/x00nullbit/CVE-References/blob/main/CVE-2025-66835/README.md](https://github.com/x00nullbit/CVE-References/blob/main/CVE-2025-66835/README.md)