CVE-2023-48643: 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 authoriz...

Description

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.10%

61.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-94

References

Timeline

Published: May 16, 2024
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2023-48643?

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.

How severe is CVE-2023-48643?

CVE-2023-48643 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.10% probability of exploitation in the next 30 days.

How do I fix CVE-2023-48643?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.