Amazon Linux 2023 : freerdp, freerdp-devel, freerdp-libs (ALAS2023-2026-1433)

high Nessus Plugin ID 299562

Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-1433 advisory.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a race condition between the RDPGFX dynamic virtual channel thread and the SDL render thread leads to a heap use-after-free.
Specifically, an escaped pointer to sdl->primary (SDL_Surface) is accessed after it has been freed during RDPGFX ResetGraphics handling. This vulnerability is fixed in 3.20.1. (CVE-2026-22851)

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client when processing Audio Input (AUDIN) format lists. audin_process_formats reuses callback->formats_count across multiple MSG_SNDIN_FORMATS PDUs and writes past the newly allocated formats array, causing memory corruption and a crash. This vulnerability is fixed in 3.20.1. (CVE-2026-22852)

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a heap-buffer-overflow occurs in drive read when a server-controlled read length is used to read file data into an IRP output stream buffer without a hard upper bound, allowing an oversized read to overwrite heap memory. This vulnerability is fixed in 3.20.1. (CVE-2026-22854)

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a heap out-of-bounds read occurs in the smartcard SetAttrib path when cbAttrLen does not match the actual NDR buffer length.
This vulnerability is fixed in 3.20.1. (CVE-2026-22855)

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a race in the serial channel IRP thread tracking allows a heap use-after-free when one thread removes an entry from serial->IrpThreads while another reads it. This vulnerability is fixed in 3.20.1. (CVE-2026-22856)

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, global-buffer-overflow was observed in FreeRDP's Base64 decoding path. The root cause appears to be implementation-defined char signedness: on Arm/AArch64 builds, plain char is treated as unsigned, so the guard c <= 0 can be optimized into a simple c != 0 check. As a result, non-ASCII bytes (e.g., 0x80-0xFF) may bypass the intended range restriction and be used as an index into a global lookup table, causing out-of-bounds access. This vulnerability is fixed in 3.20.1. (CVE-2026-22858)

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, the URBDRC client does not perform bounds checking on server-supplied MSUSB_INTERFACE_DESCRIPTOR values and uses them as indices in libusb_udev_complete_msconfig_setup, causing an out-of-bounds read. This vulnerability is fixed in 3.20.1. (CVE-2026-22859)

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, FastGlyph parsing trusts `cbData`/remaining length and never validates against the minimum size implied by `cx/cy`.
A malicious server can trigger a client-side global buffer overflow, causing a crash (DoS). Version 3.21.0 contains a patch for the issue. (CVE-2026-23732)

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

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

Solution

Run 'dnf update freerdp --releasever 2023.10.20260216' or or 'dnf update --advisory ALAS2023-2026-1433 --releasever 2023.10.20260216' to update your system.

Plugin Details

Severity: High

ID: 299562

File Name: al2023_ALAS2023-2026-1433.nasl

Version: 1.1

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 2/19/2026

Updated: 2/19/2026

Supported Sensors: Continuous Assessment, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-22854

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 8.2

Threat Score: 6.9

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS Score Source: CVE-2026-22851

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:freerdp-libs-debuginfo, p-cpe:/a:amazon:linux:freerdp-server, p-cpe:/a:amazon:linux:freerdp-devel, p-cpe:/a:amazon:linux:libwinpr-devel, p-cpe:/a:amazon:linux:freerdp-debugsource, p-cpe:/a:amazon:linux:freerdp-libs, p-cpe:/a:amazon:linux:freerdp, p-cpe:/a:amazon:linux:freerdp-debuginfo, cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:freerdp-server-debuginfo, p-cpe:/a:amazon:linux:libwinpr, p-cpe:/a:amazon:linux:libwinpr-debuginfo

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2/18/2026

Vulnerability Publication Date: 1/14/2026

Reference Information

CVE: CVE-2026-22851, CVE-2026-22852, CVE-2026-22854, CVE-2026-22855, CVE-2026-22856, CVE-2026-22858, CVE-2026-22859, CVE-2026-23732

IAVA: 2026-A-0099

Detections

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