do_ed_script in pch.c in GNU patch through 2.7.6 does not block strings beginning with a ! character. NOTE: this is the same commit as for CVE-2019-13638, but the ! syntax is specific to ed, and is unrelated to a shell metacharacter. CREATE(Triage):(User=admin) [CVE-2018-20969|https://nvd.nist.gov/vuln/detail/CVE-2018-20969]