Amazon Linux AMI Security Advisory: ALAS-2019-1285
Advisory Release Date: 2019-09-18 21:36 Pacific
It was discovered that zsh does not properly validate the shebang of input files and it truncates it to the first 64 bytes. A local attacker may use this flaw to make zsh execute a different binary than what is expected, named with a substring of the shebang one.(CVE-2018-13259 )
Run yum update zsh to update your system.