Description
FreeRDP before 3.29.0 contains a reachable assertion (WINPR_ASSERT(OutputBufferLength == BytesReturned)) in serial_process_irp_device_control() in channels/serial/client/serial_main.c. When serial device redirection is enabled and a server-controlled IRP_MJ_DEVICE_CONTROL request specifies an unsupported IOCTL with a non-zero OutputBufferLength, CommDeviceIoControl() can fail with BytesReturned = 0, causing the mismatch to trigger the assertion and abort the client process (denial of service).
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| FreeRDP | FreeRDP | < 3.29.0 | 3.29.0 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | freerdp3 | 3.29.0+dfsg-1 | — |
| Debian 13 | freerdp3 | No fix yet | — |
| Debian 12 | freerdp2 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.26.04.1 | — |
| Ubuntu 24.04 LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.24.04.1 | — |
| Ubuntu 22.04 LTS | freerdp2 | No fix yet | — |
| Ubuntu 18.04 LTS | freerdp | No fix yet | — |
| Ubuntu 16.04 LTS | freerdp | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | freerdp2 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | freerdp2 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | freerdp2 | No fix yet | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | freerdp +5 | 2:3.6.3-1.amzn2023.0.15 | ALAS2023-2026-2111 |
Advisories 2
- WID-SEC-2026-2384 FreeRDP: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 28, 2026
- ALAS2023-2026-2111 Important: freerdp security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 31, 2026
References
- GitHub Security Advisory (GHSA-pfxq-3qmw-8vjx) vendor-advisory
- Patch Commit patch
- Patch Commit patch
- VulnCheck Advisory: FreeRDP before 3.29.0 Denial of Service via serial DeviceControl third-party-advisory