CVE-2023-48643: Shrubbery tac_plus 2.x, 3.x. (CVSS 9.8)

Shrubbery tac_plus 2.x, 3.x.

Shrubbery tac_plus 2.x, 3.x. and 4.x through F4.0.4.28 allows unauthenticated Remote Command Execution. The product allows users to configure authorization checks as shell commands through the tac_plus.cfg configuration file. These are executed when a client sends an authorization request with a username that has pre-authorization directives configured. However, it is possible to inject additional commands into these checks because strings from TACACS+ packets are used as command-line arguments. If the installation lacks a a pre-shared secret (there is no pre-shared secret by default), then the injection can be triggered without authentication. (The attacker needs to know a username configured to use a pre-authorization command.) NOTE: this is related to CVE-2023-45239 but the issue is in the original Shrubbery product, not Meta's fork.

Description from the National Vulnerability Database, published by MITRE

What it means for a small business

If your business uses tac_plus_2x, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

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 1.2%, higher than 67% of CVEs. That’s above average: worth scheduling this week. Scored October 28, 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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