xrdp up to 0.9.22 Session auth_start_session exceptional condition

Summaryinfo

A vulnerability was found in xrdp up to 0.9.22. It has been classified as problematic. The impacted element is the function auth_start_session of the component Session Handler. The manipulation leads to exceptional condition. This vulnerability is referenced as CVE-2023-40184. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in xrdp up to 0.9.22. It has been rated as problematic. This issue affects the function auth_start_session of the component Session Handler. The manipulation with an unknown input leads to a exceptional condition vulnerability. Using CWE to declare the problem leads to CWE-755. The product does not handle or incorrectly handles an exceptional condition. Impacted is availability. The summary by CVE is:

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.

The weakness was published 08/30/2023 as GHSA-f489-557v-47jq. It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2023-40184 since 08/09/2023. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 236872 (Debian dla-4166 : xrdp - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 0.9.23 eliminates this vulnerability. Applying the patch a111a0fdfe2421ef600e40708b5f0168594cfb23 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (236872). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• xrdp

Version

• 0.9.0
• 0.9.1
• 0.9.2
• 0.9.3
• 0.9.4
• 0.9.5
• 0.9.6
• 0.9.7
• 0.9.8
• 0.9.9
• 0.9.10
• 0.9.11
• 0.9.12
• 0.9.13
• 0.9.14
• 0.9.15
• 0.9.16
• 0.9.17
• 0.9.18
• 0.9.19
• 0.9.20
• 0.9.21
• 0.9.22

License

• open-source

CPE 2.3info

• 🔍
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CPE 2.2info

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