CVE-2020-4044Network attack vector

Service crash via oversized sesman protocol messages

Published Jun 30, 2020 · Updated Aug 4, 2024

Stack-based buffer overflow in neutrinolabs xrdp before 0.9.13.1 allows remote attackers to crash xrdp-sesman through port 3350. The sesman SCP parser fails to reject oversized client messages before receive processing; the fix imposes an 8,192-byte message ceiling. After the crash, a local user can bind an impostor service to port 3350, capture submitted credentials, control login decisions, and hijack xorgxrdp sessions.

CVSS severity7.5
High
EPSS probability2.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in neutrinolabs xrdp before 0.9.13.1 allows remote attackers to crash xrdp-sesman through port 3350. The sesman SCP parser fails to reject oversized client messages before receive processing; the fix imposes an 8,192-byte message ceiling. After the crash, a local user can bind an impostor service to port 3350, capture submitted credentials, control login decisions, and hijack xorgxrdp sessions.

The record

CVE
CVE-2020-4044
Published
Jun 30, 2020
Updated
Aug 4, 2024
Vendor
neutrinolabs
Product
xrdp
Classifications
CWE-121, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 30, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.9.13.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

neutrinolabs · xrdpversion=< 0.9.13.1

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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