pgAgent scheduled batch job scripts are created in a predictable temporary directory potentially allowing a denial of service

When batch jobs are executed by pgAgent, a script is created in a temporary directory and then executed. In versions of pgAgent prior to 4.2.3, an insufficiently seeded random number generator is used when generating the directory name, leading to the possibility for a local attacker to pre-create the directory and thus prevent pgAgent from executing jobs, disrupting scheduled tasks.