acpid.c in acpid before 2.0.9 does not properly handle a situation in which a process has connected to acpid.socket but is not reading any data, which allows local users to cause a denial of service (daemon hang) via a crafted application that performs a connect system call but no read system calls.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.