Description
FreeRDP before 3.32.0 contains a divide-by-zero vulnerability in the freerdp-shadow-cli shadow server: the frame id in a client's Frame Acknowledge PDU is stored without a range check, so the in-flight frame count in shadow_encoder_inflight_frames() can underflow. An authenticated client can acknowledge a frame id one greater than the last frame sent, causing shadow_encoder_create_frame_id() to divide by zero (SIGFPE) and terminate the process, disconnecting all viewers.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| FreeRDP | FreeRDP | < 3.32.0 | 3.32.0 |
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 | 3.32.0+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 | 3.32.0+dfsg-0ubuntu0.26.04.1 | — |
| Ubuntu 24.04 LTS | freerdp3 | 3.32.0+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 | 2:3.32.1-1.amzn2023.0.1 | ALAS2023-2026-3307 |
Advisories 2
- WID-SEC-2026-3535 FreeRDP: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Nov 11, 2026
- ALAS2023-2026-3307 Important: freerdp security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 26, 2026
References
- GitHub Security Advisory (GHSA-6vjv-4hm3-6698) vendor-advisory
- VulnCheck Advisory: FreeRDP before 3.32.0 Shadow Server Divide-by-Zero via Frame Acknowledge PDU third-party-advisory