An issue was discovered in Opsview Monitor Agent 6.8. An unauthenticated remote attacker can call check_nrpe against affected targets, specifying known NRPE plugins, which in default installations are configured to accept command control characters and pass them to command-line interpreters for NRPE plugin execution. This allows the attacker to escape NRPE plugin execution and execute commands remotely on the target as NT_AUTHORITY\SYSTEM.
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.