CVE-2026-111373
Received Received - Intake

NULL Pointer Dereference in FreeRDP WebSocket Transport

Publication date: 2026-10-16

Last updated on: 2026-10-16

Assigner: VulnCheck

Description
FreeRDP before 3.32.0 contains a NULL pointer dereference vulnerability in the websocket transport that allows a malicious gateway to crash clients by sending zero-length pings. When the payload length is zero, websocket_reply_pong passes a nullptr stream to websocket_reply_close, triggering an assertion failure that terminates the client process and causes denial of service.

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Meta Information

Published
2026-10-16
Last Modified
2026-10-16
Generated
2026-10-16
AI Q&A
2026-10-16
EPSS Evaluated
N/A
NVD
CVE-2026-111373
EUVD
EUVD-2026-102554

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
FreeRDP FreeRDP 0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-476 The product dereferences a pointer that it expects to be valid but is NULL.

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Executive Summary

This vulnerability is a NULL pointer dereference flaw in FreeRDP versions before 3.32.0. It occurs in the WebSocket transport layer where a malicious gateway can crash client applications by sending zero-length WebSocket ping messages. The function websocket_reply_pong passes a null pointer to websocket_reply_close, causing an assertion failure that terminates the client process and results in a denial of service.

Detection Guidance

To detect this vulnerability, check the FreeRDP version on your system using 'xfreerdp --version' or 'apt list --installed | grep freerdp'. If the version is below 3.32.0, the system is vulnerable. Monitor network traffic for zero-length WebSocket ping messages targeting FreeRDP clients.

Impact Analysis

This vulnerability can cause denial of service by crashing FreeRDP client applications. An attacker on the network can exploit it by sending specially crafted WebSocket ping messages, leading to unexpected termination of the client process. Users may experience application crashes when connecting through a malicious gateway.

Compliance Impact

This vulnerability primarily impacts availability by causing denial of service through client crashes. It does not directly affect confidentiality or integrity of data, which are key concerns for GDPR and HIPAA. However, prolonged downtime could indirectly impact compliance by disrupting access to protected systems.

Mitigation Strategies

Upgrade FreeRDP to version 3.32.0 or later immediately. If upgrading is not possible, disable WebSocket transport in FreeRDP clients by using the '/gateway:transport:http,no-websockets' option to prevent the attack vector.

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