Amazon Linux 2 : freerdp, --advisory ALAS2-2026-3166 (ALAS-2026-3166)

high Nessus Plugin ID 299526

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of freerdp installed on the remote host is prior to 2.11.7-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3166 advisory.

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, 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 'yum update freerdp' or or 'yum update --advisory ALAS2-2026-3166' to update your system.

Plugin Details

Severity: High

ID: 299526

File Name: al2_ALAS-2026-3166.nasl

Version: 1.1

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 2/19/2026

Updated: 2/19/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, 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: 7.7

Threat Score: 6.8

Threat Vector: CVSS:4.0/E:P

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

CVSS Score Source: CVE-2026-22856

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:libwinpr, p-cpe:/a:amazon:linux:freerdp-devel, p-cpe:/a:amazon:linux:libwinpr-devel, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:freerdp-libs, p-cpe:/a:amazon:linux:freerdp, p-cpe:/a:amazon:linux:freerdp-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: 2/19/2026

Vulnerability Publication Date: 1/14/2026

Reference Information

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

IAVA: 2026-A-0099

Detections

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