CVE-2020-4033: OOB Read in RLEDECOMPRESS in FreeRDP

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-06-22 · updated 2026-06-17
Weakness: CWE-125

Description

In FreeRDP before version 2.1.2, there is an out of bounds read in RLEDECOMPRESS. All FreeRDP based clients with sessions with color depth < 32 are affected. This is fixed in version 2.1.2.

Affected products

Canonical Ubuntu Linux: 18.04, 20.04
Debian Linux: 10.0
Fedoraproject Fedora: 31, 32
FreeRDP: before 2.1.2 — fixed in 2.1.2
openSUSE Leap: 15.1

How to fix

Upgrade to a fixed version: FreeRDP 2.1.2. Check the vendor advisory for mitigations.

References

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00080.html
http://www.freerdp.com/2020/06/22/2_1_2-released
https://github.com/FreeRDP/FreeRDP/commit/0a98c450c58ec150e44781c89aa6f8e7e0f571f5
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-7rhj-856w-82p8
https://lists.debian.org/debian-lts-announce/2023/10/msg00008.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6Y35HBHG2INICLSGCIKNAR7GCXEHQACQ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XOZLH35OJWIQLM7FYDXAP2EAUBDXE76V/
https://usn.ubuntu.com/4481-1/
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00080.html
http://www.freerdp.com/2020/06/22/2_1_2-released
https://github.com/FreeRDP/FreeRDP/commit/0a98c450c58ec150e44781c89aa6f8e7e0f571f5
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-7rhj-856w-82p8

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