Description
FreeRDP before 3.29.0 improperly validates the Extended Key Usage (EKU) purpose of the peer certificate during client-side server TLS authentication. In x509_utils_verify(), when server-purpose (X509_PURPOSE_SSL_SERVER) verification fails, the code falls back to client-purpose and any-purpose verification, so a trusted, hostname-matching certificate valid only for clientAuth can be accepted as the RDP server certificate. In environments relying on EKU separation between client and server certificates, this allows a clientAuth-only certificate issued by a trusted CA to bypass server certificate purpose validation.
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 |
| Amazon Linux 2 | freerdp +4 | 2:2.11.7-1.amzn2.0.14 | ALAS2-2026-3887 |
Advisories 3
- WID-SEC-2026-2384 FreeRDP: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 28, 2026
- ALAS2-2026-3887 Important: freerdp security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Sep 9, 2026
- ALAS2023-2026-2111 Important: freerdp security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 31, 2026
References
- GitHub Security Advisory (GHSA-89c6-jjrw-96h4) vendor-advisory
- Patch Commit patch
- VulnCheck Advisory: FreeRDP before 3.29.0 TLS Certificate EKU Bypass third-party-advisory