xrdp: RDP MAC signature (dataSignature) never verified on receive — integrity bypass in non-TLS mode
Summary
xrdp: RDP MAC signature (dataSignature) never verified on receive — integrity bypass in non-TLS mode
Original description
The description as published by the source.
xrdp is an open source RDP server. In versions through 0.10.5, xrdp does not implement verification for the Message Authentication Code (MAC) signature of encrypted RDP packets when using the "Classic RDP Security" layer. While the sender correctly generates signatures, the receiving logic lacks the necessary implementation to validate the 8-byte integrity signature, causing it to be silently ignored. An unauthenticated attacker with man-in-the-middle (MITM) capabilities can exploit this missing check to modify encrypted traffic in transit without detection. It does not affect connections where the TLS security layer is enforced. This issue has been fixed in version 0.10.6. If users are unable to immediately upgrade, they should configure xrdp.ini to enforce TLS security (security_layer=tls) to ensure end-to-end integrity.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-32105 xrdp
- Ubuntu UBUNTU-CVE-2026-32105 xrdp
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- web github.com