CVE-2020-4044
Local users can perform a buffer overflow attack against the xrdp-sesman service and then impersonate it
The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. This will allow them to capture any user credentials that are submitted to XRDP and approve or reject arbitrary login credentials. For xorgxrdp sessions in particular, this allows an unauthorized user to hijack an existing session. This is a buffer overflow attack, so there may be a risk of arbitrary code execution as well.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.5
Local users can perform a buffer overflow attack against the xrdp-sesman service and then impersonate it
The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. This will allow them to capture any user credentials that are submitted to XRDP and approve or reject arbitrary login credentials. For xorgxrdp sessions in particular, this allows an unauthorized user to hijack an existing session. This is a buffer overflow attack, so there may be a risk of arbitrary code execution as well.
- Record
CVE-2020-4044- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-121
- Updated
- 2026-11-02
EUVDEUVD-2020-25303
7.5
The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. This will allow them to capture any user credentials that are submitted to XRDP and approve or reject arbitrary login credentials. For xorgxrdp sessions in particular, this allows an unauthorized user to hijack an existing session. This is a buffer overflow attack, so there may be a risk of arbitrary code execution as well.
- Record
EUVD-2020-25303- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
NVD
7.5
The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. This will allow them to capture any user credentials that are submitted to XRDP and approve or reject arbitrary login credentials. For xorgxrdp sessions in particular, this allows an unauthorized user to hijack an existing session. This is a buffer overflow attack, so there may be a risk of arbitrary code execution as well.
- Record
CVE-2020-4044- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 4.6 Medium
AV:L/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-121
- Updated
- 2026-11-02
OSVALPINE-CVE-2020-4044
7.8
The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. This will allow them to capture any user credentials that are submitted to XRDP and approve or reject arbitrary login credentials. For xorgxrdp sessions in particular, this allows an unauthorized user to hijack an existing session. This is a buffer overflow attack, so there may be a risk of arbitrary code execution as well.
- Record
ALPINE-CVE-2020-4044- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
OSV
7.8
The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. This will allow them to capture any user credentials that are submitted to XRDP and approve or reject arbitrary login credentials. For xorgxrdp sessions in particular, this allows an unauthorized user to hijack an existing session. This is a buffer overflow attack, so there may be a risk of arbitrary code execution as well.
- Record
CVE-2020-4044- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2020-4044
7.8
The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. This will allow them to capture any user credentials that are submitted to XRDP and approve or reject arbitrary login credentials. For xorgxrdp sessions in particular, this allows an unauthorized user to hijack an existing session. This is a buffer overflow attack, so there may be a risk of arbitrary code execution as well.
- Record
DEBIAN-CVE-2020-4044- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Show 11 moreShow less
OSVUBUNTU-CVE-2020-4044
7.8
The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. This will allow them to capture any user credentials that are submitted to XRDP and approve or reject arbitrary login credentials. For xorgxrdp sessions in particular, this allows an unauthorized user to hijack an existing session. This is a buffer overflow attack, so there may be a risk of arbitrary code execution as well.
- Record
UBUNTU-CVE-2020-4044- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVMGASA-2021-0016 No score
Updated xrdp packages fix security vulnerability
Ashley Newson discovered that the XRDP sessions manager was susceptible to denial of service. A local attacker can further take advantage of this flaw to impersonate the XRDP sessions manager and capture any user credentials that are submitted to XRDP, approve or reject arbitrary login credentials or to hijack existing sessions for xorgxrdp sessions (CVE-2020-4044).
- Record
MGASA-2021-0016- Updated
- 2026-11-02
OSVopenSUSE-SU-2020:0999-1 No score
Security update for xrdp
This update for xrdp fixes the following issues:
- Security fixes (bsc#1173580, CVE-2020-4044):
- Add patches:
- xrdp-cve-2020-4044-fix-0.patch
- xrdp-cve-2020-4044-fix-1.patch
- Rebase SLE patch:
- xrdp-fate318398-change-expired-password.patch
- Add patches:
This update was imported from the SUSE:SLE-15:Update update project.
- Record
openSUSE-SU-2020:0999-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2020:1200-1 No score
Security update for xrdp
This update for xrdp fixes the following issues:
- Update to version 0.9.13.1
- This is a security fix release that includes fixes for the following local buffer overflow vulnerability (bsc#1173580): CVE-2020-4044
This update was imported from the SUSE:SLE-15-SP2:Update update project.
- Record
openSUSE-SU-2020:1200-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:11526-1 No score
libpainter0-0.9.15-2.2 on GA media
These are all security issues fixed in the libpainter0-0.9.15-2.2 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:11526-1- Updated
- 2026-11-02
OSVSUSE-SU-2020:1918-1 No score
Security update for xrdp
This update for xrdp fixes the following issues:
- Security fixes (bsc#1173580, CVE-2020-4044):
- Add patches:
- xrdp-cve-2020-4044-fix-0.patch
- xrdp-cve-2020-4044-fix-1.patch
- Rebase SLE patch:
- xrdp-fate318398-change-expired-password.patch
- Add patches:
- Record
SUSE-SU-2020:1918-1- Updated
- 2026-11-02
OSVSUSE-SU-2020:1933-1 No score
Security update for xrdp
This update for xrdp fixes the following issues:
- Security fixes (bsc#1173580, CVE-2020-4044):
- Add patches:
- xrdp-cve-2020-4044-fix-0.patch
- xrdp-cve-2020-4044-fix-1.patch
- Rebase SLE patch:
- xrdp-fate318398-change-expired-password.patch
- Add patches:
- Record
SUSE-SU-2020:1933-1- Updated
- 2026-11-02
OSVSUSE-SU-2020:1943-1 No score
Security update for xrdp
This update for xrdp provides the following fix:
- CVE-2020-4044: xrdp-sesman can be crashed remotely over port 3350 (bsc#1173580).
- Fixed an issue where xrdp-sesman could not restart (bsc#1155952).
- Fixed an issue where xrdp could not start due to an error in the service file use absolute path in ExecStart (bsc#1155789).
- Fixed a PAM error after 2nd xrdp session after logout (bsc#1153471).
- Fixed a crash in xrdp-sesman, caused by terminating and reconnecting an xrdp session (bsc#1152711).
- Fixed a failure in RDP session recovery (bsc#1150584).
- Fixed a process leak (bsc#1144379).
- Let systemd handle the daemons, fixing daemon start failures. (bsc#1138954, bsc#1144327)
- Don't try to create .vnc directory if it already exists. (bsc#1157860)
- Record
SUSE-SU-2020:1943-1- Updated
- 2026-11-02
OSVSUSE-SU-2020:1991-1 No score
Security update for xrdp
This update for xrdp fixes the following issues:
- Security fixes (bsc#1173580, CVE-2020-4044):
- Add patches:
- xrdp-cve-2020-4044-fix-0.patch
- xrdp-cve-2020-4044-fix-1.patch
- Rebase SLE patch:
- xrdp-fate318398-change-expired-password.patch
- Add patches:
- Update patch:
- xrdp-Allow-sessions-with-32-bpp.patch.patch
- Record
SUSE-SU-2020:1991-1- Updated
- 2026-11-02
OSVSUSE-SU-2020:2142-1 No score
Security update for xrdp
This update for xrdp fixes the following issues:
- Update to version 0.9.13.1
- This is a security fix release that includes fixes for the following local buffer overflow vulnerability (bsc#1173580): CVE-2020-4044
- Record
SUSE-SU-2020:2142-1- Updated
- 2026-11-02
OSVUSN-6469-1 No score
xrdp vulnerability
Ashley Newson discovered that xrdp incorrectly handled memory when processing certain incoming connections. An attacker could possibly use this issue to cause a denial of service or arbitrary code execution.
- Record
USN-6469-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
xrdpAlpine:v3.12 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpAlpine:v3.13 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpAlpine:v3.14 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpAlpine:v3.15 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpAlpine:v3.16 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpAlpine:v3.17 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpAlpine:v3.18 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpAlpine:v3.19 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpAlpine:v3.20 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpAlpine:v3.21 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
Show 39 moreShow less
| Package | Affected | Fixed |
|---|---|---|
xrdpAlpine:v3.22 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpAlpine:v3.23 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpAlpine:v3.24 |
before 0.9.13.1-r0 | 0.9.13.1-r0 |
xrdpDebian:12 |
before 0.9.12-1.1 | 0.9.12-1.1 |
xrdpDebian:13 |
before 0.9.12-1.1 | 0.9.12-1.1 |
xrdpDebian:14 |
before 0.9.12-1.1 | 0.9.12-1.1 |
xrdpDebian:9 |
before 0.9.1-9+deb9u4, plus listed versions 0.9.1-90.9.1-9+deb9u10.9.1-9+deb9u20.9.1-9+deb9u3 |
0.9.1-9+deb9u4 |
xrdpDebian:10 |
before 0.9.9-1+deb10u1, plus listed versions 0.9.9-1 |
0.9.9-1+deb10u1 |
xrdpMageia:7 |
before 0.9.10-1.1.mga7 | 0.9.10-1.1.mga7 |
xrdpSUSE:Linux Enterprise Server 12 SP5 |
before 0.9.10-3.3.1 | 0.9.10-3.3.1 |
xrdpSUSE:Linux Enterprise Server for SAP Applications 12 SP5 |
before 0.9.10-3.3.1 | 0.9.10-3.3.1 |
xrdpSUSE:Linux Enterprise Module for Basesystem 15 SP1 |
before 0.9.6-4.8.1 | 0.9.6-4.8.1 |
xrdpSUSE:Linux Enterprise High Performance Computing 15-ESPOS |
before 0.9.6-4.8.1 | 0.9.6-4.8.1 |
xrdpSUSE:Linux Enterprise High Performance Computing 15-LTSS |
before 0.9.6-4.8.1 | 0.9.6-4.8.1 |
xrdpSUSE:Linux Enterprise Server 15-LTSS |
before 0.9.6-4.8.1 | 0.9.6-4.8.1 |
xrdpSUSE:Linux Enterprise Server for SAP Applications 15 |
before 0.9.6-4.8.1 | 0.9.6-4.8.1 |
xrdpSUSE:OpenStack Cloud 7 From an advisory covering 2 CVEs |
before 0.9.0~git.1456906198.f422461-16.20.1 | 0.9.0~git.1456906198.f422461-16.20.1 |
xrdpSUSE:Linux Enterprise Server for SAP Applications 12 SP2 From an advisory covering 2 CVEs |
before 0.9.0~git.1456906198.f422461-16.20.1 | 0.9.0~git.1456906198.f422461-16.20.1 |
xrdpSUSE:Linux Enterprise Server 12 SP2-LTSS From an advisory covering 2 CVEs |
before 0.9.0~git.1456906198.f422461-16.20.1 | 0.9.0~git.1456906198.f422461-16.20.1 |
xrdpSUSE:Linux Enterprise Server 12 SP2-BCL From an advisory covering 2 CVEs |
before 0.9.0~git.1456906198.f422461-16.20.1 | 0.9.0~git.1456906198.f422461-16.20.1 |
xrdpSUSE:HPE Helion OpenStack 8 |
before 0.9.0~git.1456906198.f422461-21.27.1 | 0.9.0~git.1456906198.f422461-21.27.1 |
xrdpSUSE:OpenStack Cloud 8 |
before 0.9.0~git.1456906198.f422461-21.27.1 | 0.9.0~git.1456906198.f422461-21.27.1 |
xrdpSUSE:OpenStack Cloud 9 |
before 0.9.0~git.1456906198.f422461-21.27.1 | 0.9.0~git.1456906198.f422461-21.27.1 |
xrdpSUSE:OpenStack Cloud Crowbar 8 |
before 0.9.0~git.1456906198.f422461-21.27.1 | 0.9.0~git.1456906198.f422461-21.27.1 |
xrdpSUSE:OpenStack Cloud Crowbar 9 |
before 0.9.0~git.1456906198.f422461-21.27.1 | 0.9.0~git.1456906198.f422461-21.27.1 |
xrdpSUSE:Linux Enterprise Server for SAP Applications 12 SP3 |
before 0.9.0~git.1456906198.f422461-21.27.1 | 0.9.0~git.1456906198.f422461-21.27.1 |
xrdpSUSE:Linux Enterprise Server for SAP Applications 12 SP4 |
before 0.9.0~git.1456906198.f422461-21.27.1 | 0.9.0~git.1456906198.f422461-21.27.1 |
xrdpSUSE:Linux Enterprise Server 12 SP3-LTSS |
before 0.9.0~git.1456906198.f422461-21.27.1 | 0.9.0~git.1456906198.f422461-21.27.1 |
xrdpSUSE:Linux Enterprise Server 12 SP3-BCL |
before 0.9.0~git.1456906198.f422461-21.27.1 | 0.9.0~git.1456906198.f422461-21.27.1 |
xrdpSUSE:Linux Enterprise Server 12 SP4-LTSS |
before 0.9.0~git.1456906198.f422461-21.27.1 | 0.9.0~git.1456906198.f422461-21.27.1 |
xrdpSUSE:Enterprise Storage 5 |
before 0.9.0~git.1456906198.f422461-21.27.1 | 0.9.0~git.1456906198.f422461-21.27.1 |
xrdpSUSE:Linux Enterprise Module for Basesystem 15 SP2 |
before 0.9.13.1-4.3.1 | 0.9.13.1-4.3.1 |
xrdpUbuntu:Pro:14.04:LTS |
before 0.6.0-1ubuntu0.1+esm2, plus listed versions 0.6.0-10.6.0-1ubuntu0.10.6.0-1ubuntu0.1+esm1 |
0.6.0-1ubuntu0.1+esm2 |
xrdpUbuntu:Pro:16.04:LTS |
before 0.6.1-2ubuntu0.3+esm2, plus listed versions 0.6.1-20.6.1-2ubuntu0.10.6.1-2ubuntu0.30.6.1-2ubuntu0.3+esm1 |
0.6.1-2ubuntu0.3+esm2 |
xrdpUbuntu:Pro:18.04:LTS |
before 0.9.5-2ubuntu0.1~esm1, plus listed versions 0.9.1-90.9.4-10.9.4-20.9.4-30.9.4-4 Show 4 moreShow less0.9.4-50.9.5-10.9.5-1build10.9.5-2 |
0.9.5-2ubuntu0.1~esm1 |
xrdpUbuntu:20.04:LTS |
before 0.9.12-1ubuntu0.1, plus listed versions 0.9.9-10.9.12-1 |
0.9.12-1ubuntu0.1 |
xrdpopenSUSE:Leap 15.1 |
before 0.9.6-lp151.4.6.1 | 0.9.6-lp151.4.6.1 |
xrdpopenSUSE:Leap 15.2 |
before 0.9.13.1-lp152.3.3.1 | 0.9.13.1-lp152.3.3.1 |
xrdpopenSUSE:Tumbleweed From an advisory covering 4 CVEs |
before 0.9.15-2.2 | 0.9.15-2.2 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected, aliases, references | OSV | |
| aliases | EUVD | |
| first indexed | CVE List, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-4044 is a high vulnerability (CVSS 7.5) in Neutrinolabs Xrdp, published June 30, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.33%, the 83rd percentile. Fixed in xrdp 0.9.13.1-r0.
References
github.com/neutrinolabs/xrdp/security/advisories/GHSA-j9fv-6fwf-p3g4
github.com/neutrinolabs/xrdp/releases/tag/v0.9.13.1
github.com/neutrinolabs/xrdp/commit/0c791d073d0eb344ee7aaafd221513dc9226762c
lists.opensuse.org/opensuse-security-announce/2020-07/msg00036.html
debian.org/security/2020/dsa-4737
lists.debian.org/debian-lts-announce/2020/08/msg00015.html
Show 30 moreShow less
lists.opensuse.org/opensuse-security-announce/2020-08/msg00037.html
security.alpinelinux.org/vuln/CVE-2020-4044
security-tracker.debian.org/tracker/CVE-2020-4044
advisories.mageia.org/MGASA-2021-0016.html
bugs.mageia.org/show_bug.cgi?id=26931
lists.fedoraproject.org/archives/list/[email protected]/thread/7FYD6USHZXDI2EAZVGOVFMAE7ILP3SPL
suse.com/support/update/announcement/2020/suse-su-20201918-1
bugzilla.suse.com/1173580
suse.com/security/cve/CVE-2020-4044
suse.com/support/update/announcement/2020/suse-su-20201933-1
suse.com/support/update/announcement/2020/suse-su-20201943-1
bugzilla.suse.com/1138954
bugzilla.suse.com/1144327
bugzilla.suse.com/1144379
bugzilla.suse.com/1150584
bugzilla.suse.com/1152711
bugzilla.suse.com/1153471
bugzilla.suse.com/1155789
bugzilla.suse.com/1155952
bugzilla.suse.com/1157860
suse.com/security/cve/CVE-2017-6967
suse.com/support/update/announcement/2020/suse-su-20201991-1
suse.com/support/update/announcement/2020/suse-su-20202142-1
ubuntu.com/security/CVE-2020-4044
ubuntu.com/security/notices/USN-6469-1
cve.org/CVERecord?id=CVE-2020-4044
lists.opensuse.org/archives/list/[email protected]/thread/EQUUIOUYGTDXTBN4XZOJYF4OAWH4AGKI
lists.opensuse.org/archives/list/[email protected]/thread/R2LZ7GPOGYBOGEESSXWFJQM62NIRACWR
suse.com/security/cve/CVE-2013-1430
suse.com/security/cve/CVE-2017-16927