Copyright © 2012 Red Hat, Inc. All rights reserved. Important 2026-08-19T18:00:52 freerdp: FreeRDP: Arbitrary code execution via heap buffer overflow in Opus audio decode 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H CWE-120

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, freerdp_dsp_decode_opus in libfreerdp/codec/dsp.c calls Stream_EnsureRemainingCapacity on context->common.buffer even though opus_decode writes decoded PCM into the caller-supplied out stream. A malicious RDP server that negotiates WAVE_FORMAT_OPUS with a client built with WITH_OPUS enabled and WITH_DSP_FFMPEG disabled can make libopus write a large decoded frame beyond the 4096-byte StreamPool_Take destination used by channels/rdpsnd/client/rdpsnd_main.c. This can corrupt the client heap, crash the client, and may permit code execution. This issue is fixed in version 3.28.0.

A flaw was found in FreeRDP, a free implementation of the Remote Desktop Protocol. A malicious Remote Desktop Protocol (RDP) server can exploit a heap buffer overflow vulnerability during Opus audio decoding. This occurs when the server negotiates Opus audio with a vulnerable client, causing the client to write data beyond an allocated memory buffer. This can lead to client crashes, memory corruption, and potentially allow the malicious server to execute arbitrary code on the client system.

A heap buffer overflow vulnerability was found in FreeRDP's DSP audio codec module (`libfreerdp/codec/dsp.c`). When built with `WITH_OPUS` and without `WITH_DSP_FFMPEG`, `freerdp_dsp_decode_opus` fails to validate destination buffer capacity when handling `WAVE_FORMAT_OPUS` streams. A malicious RDP server can transmit an oversized Opus frame, causing `libopus` to write beyond the 4096-byte client buffer allocated by the `rdpsnd` channel. This leads to client heap corruption, application crashes, or potential remote code execution. To mitigate this vulnerability, disable audio redirection on client connections by omitting audio parameters (such as `/sound` or `/audio`) in `xfreerdp` to bypass client-side DSP audio decoding. Red Hat Enterprise Linux 10 2026-08-31T00:00:00Z RHSA-2026:61378 freerdp-2:3.10.3-12.el10_2.10 Red Hat Enterprise Linux 10.0 Extended Update Support 2026-09-17T00:00:00Z RHSA-2026:68706 freerdp-2:3.10.3-3.el10_0.16 Red Hat Enterprise Linux 6 Not affected freerdp Red Hat Enterprise Linux 7 Not affected freerdp Red Hat Enterprise Linux 8 Not affected freerdp Red Hat Enterprise Linux 9 Not affected freerdp https://www.cve.org/CVERecord?id=CVE-2026-63633 https://nvd.nist.gov/vuln/detail/CVE-2026-63633 https://github.com/FreeRDP/FreeRDP/commit/0ed1f95d36913581cf31124f94eb5843d4263eae https://github.com/FreeRDP/FreeRDP/pull/12993 https://github.com/FreeRDP/FreeRDP/releases/tag/3.28.0 https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-72j9-356v-88xq