CVE-2020-3442: The DuoConnect client enables users to establish SSH connections to hosts protected by a DNG instance.

The DuoConnect client enables users to establish SSH connections to hosts protected by a DNG instance.

The DuoConnect client enables users to establish SSH connections to hosts protected by a DNG instance. When a user initiates an SSH connection to a DNG-protected host for the first time using DuoConnect, the user’s browser is opened to a login screen in order to complete authentication determined by the contents of the '-relay' argument. If the ‘-relay’ is set to a URL beginning with "http://", then the browser will initially attempt to load the URL over an insecure HTTP connection, before being immediately redirected to HTTPS (in addition to standard redirect mechanisms, the DNG uses HTTP Strict Transport Security headers to enforce this). After successfully authenticating to a DNG, DuoConnect stores an authentication token in a local system cache, so users do not have to complete this browser-based authentication workflow for every subsequent SSH connection. These tokens are valid for a configurable period of time, which defaults to 8 hours. If a user running DuoConnect already has a valid token, then instead of opening a web browser, DuoConnect directly contacts the DNG, again using the configured '-relay' value, and sends this token, as well as the intended SSH server hostname

Description from the National Vulnerability Database, published by psirt@cisco.com

What it means for a small business

DUO Connect is network equipment or remote-access software: the box between your office and the internet. These are a favorite target because breaking one opens the whole office.

If an IT provider set it up, ask them to confirm the firmware version and the date it was updated. If nobody looks after it, that's the bigger problem.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.15%, higher than 4% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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