CVE-2023-40184

Published: 30 August 2023

xrdp is an open source remote desktop protocol (RDP) server. In versions prior to 0.9.23 improper handling of session establishment errors allows bypassing OS-level session restrictions. The `auth_start_session` function can return non-zero (1) value on, e.g., PAM error which may result in in session restrictions such as max concurrent sessions per user by PAM (ex ./etc/security/limits.conf) to be bypassed. Users (administrators) don't use restrictions by PAM are not affected. This issue has been addressed in release version 0.9.23. Users are advised to upgrade. There are no known workarounds for this issue.

Priority

Cvss 3 Severity Score

6.5

Score breakdown

Status

Package	Release	Status
xrdp Launchpad, Ubuntu, Debian	bionic	Released (0.9.5-2ubuntu0.1~esm2) Available with Ubuntu Pro
	focal	Released (0.9.12-1ubuntu0.1+esm1) Available with Ubuntu Pro
	jammy	Released (0.9.17-2ubuntu2+esm1) Available with Ubuntu Pro
	lunar	Ignored (end of life, was needs-triage)
	mantic	Needs triage
	noble	Needs triage
	trusty	Released (0.6.0-1ubuntu0.1+esm3) Available with Ubuntu Pro or Ubuntu Pro (Infra-only)
	upstream	Released (0.9.23)
	xenial	Released (0.6.1-2ubuntu0.3+esm3) Available with Ubuntu Pro

Severity score breakdown

Parameter	Value
Base score	6.5
Attack vector	Network
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

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