Symless Synergy 3.x < 3.9.1 RSA Signature Forgery (node-forge)

high Nessus Plugin ID 374139

Synopsis

An application installed on the remote host is affected by a signature forgery vulnerability.

Description

The version of Symless Synergy installed on the remote host is 3.x prior to 3.9.1. It is, therefore, affected by a vulnerability in the bundled node-forge library, which Synergy 3 uses to create its own certificate.

- node-forge through 1.4.0 fails to validate element count in nested DigestAlgorithm sequences during RSA PKCS#1 v1.5 signature verification. Attackers can embed garbage bytes inside the DigestAlgorithm sequence to forge valid signatures for arbitrary messages using low-exponent RSA keys. This is an incomplete fix for CVE-2026-33894. (CVE-2026-85393)

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

Solution

Upgrade to Symless Synergy version 3.9.1 or later.

Plugin Details

Severity: High

ID: 374139

File Name: symless_synergy_3_9_1.nasl

Version: 1.1

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 10/30/2026

Updated: 10/30/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.63

CVSS v2

Risk Factor: High

Base Score: 7.8

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

CVSS Score Source: CVE-2026-85393

CVSS v3

Risk Factor: High

Base Score: 7.5

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

Vulnerability Information

CPE: cpe:/a:symless:synergy

Patch Publication Date: 10/29/2026

Vulnerability Publication Date: 9/3/2026

Reference Information

CVE: CVE-2026-85393

Detections

Analytics