CVE-2026-33952
Assertion Failure DoS in FreeRDP RPC-over-HTTP Gateway Transport
Publication date: 2026-03-30
Last updated on: 2026-04-02
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| freerdp | freerdp | to 3.24.2 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-617 | The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in FreeRDP, a free implementation of the Remote Desktop Protocol. Before version 3.24.2, an unvalidated auth_length field read from the network causes a WINPR_ASSERT() failure in the function rts_read_auth_verifier_no_checks(). This failure leads to the FreeRDP client crashing with a SIGABRT signal when connecting through a malicious RDP Gateway.
The issue is a pre-authentication denial of service affecting all FreeRDP clients that use RPC-over-HTTP gateway transport. The assertion failure is active in default release builds with verbose assertions enabled. The vulnerability has been fixed in version 3.24.2.
How can this vulnerability impact me? :
This vulnerability can cause FreeRDP clients to crash unexpectedly when connecting through a malicious RDP Gateway. This results in a denial of service, preventing legitimate users from establishing remote desktop connections.
Since the crash occurs before authentication, it can be exploited by attackers to disrupt services without needing valid credentials.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, update all FreeRDP clients to version 3.24.2 or later, where the issue has been patched.
Avoid using RPC-over-HTTP gateway transport with vulnerable FreeRDP clients until they are updated.