CVE-2021-33191: Apache Nifi Minifi C++

Critical severity, CVSS 9.8. EPSS: 4% chance of exploitation in the next 30 days.

From Apache NiFi MiNiFi C++ version 0.5.0 the c2 protocol implements an "agent-update" command which was designed to patch the application binary. This "patching" command defaults to calling a trusted binary, but might be modified to an arbitrary value through a "c2-update" command. Said command is then executed using the same privileges as the application binary. This was addressed in version 0.10.0

Affected products

• Apache Nifi Minifi C++: from 0.5.0, before 0.10.0 (fixed in 0.10.0)

Published 2021-08-24. Last modified 2026-06-17.