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Fencer Vulns
medium 5.8

CVE-2021-41159 json

Improper client input validation for FreeRDP gateway connections allows to overwrite memory

published 2021-10-21 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-28269

cvss
5.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. All FreeRDP clients prior to version 2.4.1 using gateway connections (`/gt:rpc`) fail to validate input data. A malicious gateway might allow client memory to be written out of bounds. This issue has been resolved in version 2.4.1. If you are unable to update then use `/gt:http` rather than /gt:rdp connections if possible or use a direct connection without a gateway.

Patch / fix

  • freerdp freerdp 2.4.1
  • freerdp2 Debian 12 2.4.1+dfsg1-1

debian advisories DEBIAN-CVE-2021-41159

  • freerdp2 Ubuntu 18.04 LTS 2.2.0+dfsg1-0ubuntu0.18.04.2
  • freerdp2 Ubuntu 20.04 LTS 2.2.0+dfsg1-0ubuntu0.20.04.2
  • freerdp2 Ubuntu 22.04 LTS 2.3.0+dfsg1-2ubuntu2

ubuntu advisories UBUNTU-CVE-2021-41159

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • freerdp RHEL 7 2.1.1-5.el7_9
  • libwinpr RHEL 7 2.1.1-5.el7_9
  • freerdp-libs RHEL 7 2.1.1-5.el7_9
  • freerdp RHEL 8 2:2.2.0-7.el8_5
  • libwinpr RHEL 8 2:2.2.0-7.el8_5
  • freerdp-libs RHEL 8 2:2.2.0-7.el8_5
  • freerdp RHEL 8.4 EUS 2:2.2.0-6.el8_4
  • libwinpr RHEL 8.4 EUS 2:2.2.0-6.el8_4

red hat advisories RHSA-2021:4623RHSA-2021:4620RHSA-2021:4619RHSA-2021:4621RHSA-2021:4622

  • freerdp SLE Workstation Extension 15 SP4, SLE Module for Package Hub 15 SP4, openSUSE Leap 15.4 2.4.0-150400.3.6.1
  • freerdp SLE Workstation Extension 15 SP3, SLE Module for Package Hub 15 SP3, openSUSE Leap 15.3 2.1.2-150200.15.18.1
  • freerdp SLE Workstation Extension 12 SP5, SLE Software Development Kit 12 SP5 2.1.2-12.26.1

suse advisories SUSE-SU-2022:2993-1SUSE-SU-2022:2891-1SUSE-SU-2022:2890-1

  • freerdp2 openSUSE Tumbleweed 2.4.1-1.1

opensuse advisories openSUSE-SU-2024:11591-1

  • freerdp AlmaLinux 8 2:2.2.0-7.el8_5
  • libwinpr AlmaLinux 8 2:2.2.0-7.el8_5
  • freerdp-libs AlmaLinux 8 2:2.2.0-7.el8_5

almalinux advisories ALSA-2021:4622

  • freerdp Rocky Linux 8 2:2.2.0-7.el8_5

rocky linux advisories RLSA-2021:4622

  • freerdp Alpine 3.24, Alpine 3.23, Alpine 3.22 +7 more 2.4.1-r0
  • freerdp2 Alpine 3.24, Alpine 3.23, Alpine 3.22 2.4.1-r0

alpine advisories ALPINE-CVE-2021-41159

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • freerdp Arch Linux 2:2.4.1-1

arch linux advisories AVG-2488

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-41159 updated cvss 8.8

freerdp: improper client input validation for gateway connections allows to overwrite memory

  • Red Hat CodeReady Linux Builder (v. 8) freerdp-devel 2.2.0-7.el8_5, freerdp-debuginfo 2.2.0-7.el8_5, libwinpr-debuginfo 2.2.0-7.el8_5, freerdp-debugsource 2.2.0-7.el8_5, freerdp-libs-debuginfo 2.2.0-7.el8_5
    fixed: vendor fix RHSA-2021:4622
  • Red Hat CodeReady Linux Builder EUS (v. 8.1) freerdp-devel 2.0.0-46.rc4.el8_1.5, freerdp-debuginfo 2.0.0-46.rc4.el8_1.5, libwinpr-debuginfo 2.0.0-46.rc4.el8_1.5, freerdp-debugsource 2.0.0-46.rc4.el8_1.5, freerdp-libs-debuginfo 2.0.0-46.rc4.el8_1.5
    fixed: vendor fix RHSA-2021:4620
  • Red Hat CodeReady Linux Builder EUS (v. 8.2) freerdp-devel 2.0.0-46.rc4.el8_2.5, freerdp-debuginfo 2.0.0-46.rc4.el8_2.5, libwinpr-debuginfo 2.0.0-46.rc4.el8_2.5, freerdp-debugsource 2.0.0-46.rc4.el8_2.5, freerdp-libs-debuginfo 2.0.0-46.rc4.el8_2.5
    fixed: vendor fix RHSA-2021:4621
  • Red Hat Enterprise Linux AppStream (v. 8) freerdp 2.2.0-7.el8_5, libwinpr 2.2.0-7.el8_5, freerdp-libs 2.2.0-7.el8_5
    fixed: vendor fix RHSA-2021:4622
  • Red Hat Enterprise Linux AppStream EUS (v. 8.1) freerdp 2.0.0-46.rc4.el8_1.5, libwinpr 2.0.0-46.rc4.el8_1.5, freerdp-libs 2.0.0-46.rc4.el8_1.5
    fixed: vendor fix RHSA-2021:4620
  • Red Hat Enterprise Linux AppStream EUS (v. 8.2) freerdp 2.0.0-46.rc4.el8_2.5, libwinpr 2.0.0-46.rc4.el8_2.5, freerdp-libs 2.0.0-46.rc4.el8_2.5
    fixed: vendor fix RHSA-2021:4621
  • Red Hat Enterprise Linux AppStream EUS (v.8.4) freerdp 2.2.0-6.el8_4, libwinpr 2.2.0-6.el8_4, freerdp-libs 2.2.0-6.el8_4
    fixed: vendor fix RHSA-2021:4623
  • Red Hat Enterprise Linux Client (v. 7) freerdp 2.1.1-5.el7_9, libwinpr 2.1.1-5.el7_9, freerdp-libs 2.1.1-5.el7_9 Red Hat Enterprise Linux Client Optional (v. 7) freerdp-devel 2.1.1-5.el7_9, libwinpr-devel 2.1.1-5.el7_9, freerdp-debuginfo 2.1.1-5.el7_9
    fixed: vendor fix RHSA-2021:4619
show 3 more
  • Red Hat Enterprise Linux CRB EUS (v.8.4) freerdp-devel 2.2.0-6.el8_4, freerdp-debuginfo 2.2.0-6.el8_4, libwinpr-debuginfo 2.2.0-6.el8_4, freerdp-debugsource 2.2.0-6.el8_4, freerdp-libs-debuginfo 2.2.0-6.el8_4
    fixed: vendor fix RHSA-2021:4623
  • Red Hat Enterprise Linux Server (v. 7) freerdp 2.1.1-5.el7_9, libwinpr 2.1.1-5.el7_9, freerdp-libs 2.1.1-5.el7_9 Red Hat Enterprise Linux Server Optional (v. 7) freerdp-devel 2.1.1-5.el7_9, libwinpr-devel 2.1.1-5.el7_9, freerdp-debuginfo 2.1.1-5.el7_9 Red Hat Enterprise Linux Workstation (v. 7) freerdp 2.1.1-5.el7_9, libwinpr 2.1.1-5.el7_9, freerdp-libs 2.1.1-5.el7_9 Red Hat Enterprise Linux Workstation Optional (v. 7) freerdp-devel 2.1.1-5.el7_9, libwinpr-devel 2.1.1-5.el7_9, freerdp-debuginfo 2.1.1-5.el7_9
    fixed: vendor fix RHSA-2021:4619
  • Red Hat Enterprise Linux 6 freerdp, freerdp-libs, freerdp-plugins Red Hat Enterprise Linux 9 freerdp, libwinpr, freerdp-libs
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.49% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.8 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • FreeRDP FreeRDP

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.