CVE-2023-40184 | Improper handling of session establishment errors in xrdp

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.

Published: 2023-08-30 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-40184 is rated Low Risk (28.3/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.73%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-40184

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.06% 0.73% +0.67%
2 2026-04-25 0.05% 0.06% +0.01%
3 2025-11-21 0.05%

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-40184

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
2.6 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
1.2 1.4 [email protected]
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 3.6 [email protected]

Weakness enumeration for CVE-2023-40184

OS Trackers for CVE-2023-40184

vendor priority summary link
alpine low CVE-2023-40184: 1 source package rows (xrdp); 14 state rows across 6 repos (3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 6, open 8. https://security.alpinelinux.org/vuln/CVE-2023-40184
debian not yet assigned CVE-2023-40184 not yet assigned priority: Debian including 1 source packages (xrdp), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-40184
suse medium https://www.suse.com/security/cve/CVE-2023-40184/
ubuntu medium CVE-2023-40184 medium priority: Ubuntu including 1 source packages (xrdp), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): released 6, not-affected 3, ignored 2, needs-triage 1. https://ubuntu.com/security/CVE-2023-40184

Affected software / configurations for CVE-2023-40184

Vendor Product Version Raw CPE
neutrinolabs xrdp < 0.9.23 cpe:2.3:a:neutrinolabs:xrdp:*:*:*:*:*:*:*:*

References for CVE-2023-40184

cvelogic Threat Intelligence