CVE-2026-33977

MEDIUM

FreeRDP: DoS via WINPR_ASSERT in IMA ADPCM audio decoder (dsp.c:331)

Title source: cna

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, a malicious RDP server can crash the FreeRDP client by sending audio data in IMA ADPCM format with an invalid initial step index value (>= 89). The unvalidated step index is read directly from the network and used to index into a 89-entry lookup table, triggering a WINPR_ASSERT() failure and process abort via SIGABRT. This affects any FreeRDP client that has audio redirection (RDPSND) enabled, which is the default configuration. This issue has been patched in version 3.24.2.

Scores

CVSS v3 6.5
EPSS 0.0004
EPSS Percentile 11.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-617
Status published
Products (2)
freerdp/freerdp < 3.24.2
FreeRDP/FreeRDP < 3.24.2
Published Mar 30, 2026
Tracked Since Mar 31, 2026