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 remote SUSE Linux SLES12 / SLES_SAP12 host has a package installed that is affected by multiple vulnerabilities as referenced in the SUSE-SU-2023:4873-1 advisory.

  - 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.
    (CVE-2023-40184)

  - xrdp is an open source remote desktop protocol server. Access to the font glyphs in xrdp_painter.c is not     bounds-checked . Since some of this data is controllable by the user, this can result in an out-of-bounds     read within the xrdp executable. The vulnerability allows an out-of-bounds read within a potentially     privileged process. On non-Debian platforms, xrdp tends to run as root. Potentially an out-of-bounds write     can follow the out-of-bounds read. There is no denial-of-service impact, providing xrdp is running in     forking mode. This issue has been addressed in release 0.9.23.1. Users are advised to upgrade. There are     no known workarounds for this vulnerability. (CVE-2023-42822)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 16.04 ESM / 18.04 ESM / 20.04 ESM / 22.04 ESM host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-6474-1 advisory.

    It was discovered that xrdp incorrectly handled validation of client-supplied data, which could lead to     out-of-bounds reads. An attacker could possibly use this issue to crash the program or extract sensitive     information. (CVE-2022-23479, CVE-2022-23481, CVE-2022-23483, CVE-2023-42822)

    It was discovered that xrdp improperly handled session establishment errors. An attacker could potentially     use this issue to bypass the OS-level session restrictions by PAM. (CVE-2023-40184)

    It was discovered that xrdp incorrectly handled validation of client-supplied data, which could lead to     out-of-bounds writes. An attacker could possibly use this issue to cause memory corruption or execute     arbitrary code. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS and Ubuntu 22.04 LTS.
    (CVE-2022-23468)

    It was discovered that xrdp incorrectly handled validation of client-supplied data, which could lead to     out-of-bounds reads. An attacker could possibly use this issue to crash the program or extract sensitive     information. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS and Ubuntu 22.04 LTS.
    (CVE-2022-23480, CVE-2022-23482, CVE-2022-23484)

    It was discovered that xrdp incorrectly handled validation of client-supplied data, which could lead to     out-of-bounds reads. An attacker could possibly use this issue to crash the program or extract sensitive     information. This issue only affected Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. (CVE-2022-23477,     CVE-2022-23493)

    It was discovered that xrdp incorrectly handled validation of client-supplied data, which could lead to     out-of-bounds writes. An attacker could possibly use this issue to cause memory corruption or execute     arbitrary code. This issue only affected Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. (CVE-2022-23478)

    It was discovered that xrdp incorrectly handled validation of client-supplied data, which could lead to     out-of-bounds reads. An attacker could possibly use this issue to crash the program or extract sensitive     information. This issue only affected Ubuntu 22.04 LTS. (CVE-2022-23613)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 39 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2023-5134642a68 advisory.

    Release notes for xrdp v0.9.23 (2023/08/31)

    General announcements

     - Running xrdp and xrdp-sesman on separate hosts is still supported by this release, but is now     deprecated. This is not secure. A future v1.0 release will replace the TCP socket used between these     processes with a Unix Domain Socket, and then cross-host running will not be possible.

    Security fixes

     - CVE-2023-40184: Improper handling of session establishment errors allows bypassing OS-level session     restrictions (Reported by @gafusss)

    Bug fixes

     - Environment variables set by PAM modules are no longer restricted to around 250 characters (#2712)
     - X11 clipboard clients now no longer hang when requesting a clipboard format which isn't available     (#2767)

    New features

    No new features in this release.
    Internal changes

     - Introduce release tarball generation script (#2703)
     - cppcheck version used for CI bumped to 2.11 (#2738)

    Known issues

     - On-the-fly resolution change requires the Microsoft Store version of Remote Desktop client but     sometimes crashes on connect (#1869)
     - xrdp's login dialog is not relocated at the center of the new resolution after on-the-fly resolution     change happens (#1867)

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 / openSUSE 15 host has packages installed that are affected by a vulnerability as referenced in the SUSE-SU-2023:3830-1 advisory.

  - 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.
    (CVE-2023-40184)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the c9ff1150-5d63-11ee-bbae-1c61b4739ac9 advisory.

  - 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.
    (CVE-2023-40184)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES12 / SLES_SAP12 host has a package installed that is affected by a vulnerability as referenced in the SUSE-SU-2023:3735-1 advisory.

  - 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.
    (CVE-2023-40184)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 38 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2023-b1d585e148 advisory.

    Release notes for xrdp v0.9.23 (2023/08/31)

    General announcements

     - Running xrdp and xrdp-sesman on separate hosts is still supported by this release, but is now     deprecated. This is not secure. A future v1.0 release will replace the TCP socket used between these     processes with a Unix Domain Socket, and then cross-host running will not be possible.

    Security fixes

     - CVE-2023-40184: Improper handling of session establishment errors allows bypassing OS-level session     restrictions (Reported by @gafusss)

    Bug fixes

     - Environment variables set by PAM modules are no longer restricted to around 250 characters (#2712)
     - X11 clipboard clients now no longer hang when requesting a clipboard format which isn't available     (#2767)

    New features

    No new features in this release.
    Internal changes

     - Introduce release tarball generation script (#2703)
     - cppcheck version used for CI bumped to 2.11 (#2738)

    Known issues

     - On-the-fly resolution change requires the Microsoft Store version of Remote Desktop client but     sometimes crashes on connect (#1869)
     - xrdp's login dialog is not relocated at the center of the new resolution after on-the-fly resolution     change happens (#1867)

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 37 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2023-40298f6951 advisory.

    Release notes for xrdp v0.9.23 (2023/08/31)

    General announcements

     - Running xrdp and xrdp-sesman on separate hosts is still supported by this release, but is now     deprecated. This is not secure. A future v1.0 release will replace the TCP socket used between these     processes with a Unix Domain Socket, and then cross-host running will not be possible.

    Security fixes

     - CVE-2023-40184: Improper handling of session establishment errors allows bypassing OS-level session     restrictions (Reported by @gafusss)

    Bug fixes

     - Environment variables set by PAM modules are no longer restricted to around 250 characters (#2712)
     - X11 clipboard clients now no longer hang when requesting a clipboard format which isn't available     (#2767)

    New features

    No new features in this release.
    Internal changes

     - Introduce release tarball generation script (#2703)
     - cppcheck version used for CI bumped to 2.11 (#2738)

    Known issues

     - On-the-fly resolution change requires the Microsoft Store version of Remote Desktop client but     sometimes crashes on connect (#1869)
     - xrdp's login dialog is not relocated at the center of the new resolution after on-the-fly resolution     change happens (#1867)

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
187001	SUSE SLES12 Security Update : xrdp (SUSE-SU-2023:4873-1)	Nessus	SuSE Local Security Checks	medium
185416	Ubuntu 16.04 ESM / 18.04 ESM / 20.04 ESM / 22.04 ESM : xrdp vulnerabilities (USN-6474-1)	Nessus	Ubuntu Local Security Checks	critical
185218	Fedora 39 : xrdp (2023-5134642a68)	Nessus	Fedora Local Security Checks	medium
182105	SUSE SLED15 / SLES15 / openSUSE 15 Security Update : xrdp (SUSE-SU-2023:3830-1)	Nessus	SuSE Local Security Checks	medium
182077	FreeBSD : xrdp -- Improper handling of session establishment errors allows bypassing OS-level session restrictions (c9ff1150-5d63-11ee-bbae-1c61b4739ac9)	Nessus	FreeBSD Local Security Checks	medium
181824	SUSE SLES12 Security Update : xrdp (SUSE-SU-2023:3735-1)	Nessus	SuSE Local Security Checks	medium
181205	Fedora 38 : xrdp (2023-b1d585e148)	Nessus	Fedora Local Security Checks	medium
181204	Fedora 37 : xrdp (2023-40298f6951)	Nessus	Fedora Local Security Checks	medium

Detections

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CVE-2023-40184

medium

Tenable Plugins

medium

critical

medium

medium

medium

medium

medium

medium