GNU patch through 2.7.6 contains a free(p_line[p_end]) Double Free vulnerability in the function another_hunk in pch.c that can cause a denial of service via a crafted patch file. NOTE: this issue exists because of an incomplete fix for CVE-2018-6952.

A Directory Traversal vulnerability exists in the GNU patch before 2.7.4. A remote attacker can write to arbitrary files via a symlink attack in a patch file. NOTE: this issue exists because of an incomplete fix for CVE-2015-1196.

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.

In GNU patch through 2.7.6, the following of symlinks is mishandled in certain cases other than input files. This affects inp.c and util.c.

A double free exists in the another_hunk function in pch.c in GNU patch through 2.7.6.

An issue was discovered in GNU patch through 2.7.6. There is a segmentation fault, associated with a NULL pointer dereference, leading to a denial of service in the intuit_diff_type function in pch.c, aka a "mangled rename" issue.

An issue was discovered in GNU patch before 2.7.6. Out-of-bounds access within pch_write_line() in pch.c can possibly lead to DoS via a crafted input file.

Directory traversal vulnerability in GNU patch versions which support Git-style patching before 2.7.3 allows remote attackers to write to arbitrary files with the permissions of the target user via a .. (dot dot) in a diff file name.

GNU patch 2.7.2 and earlier allows remote attackers to cause a denial of service (memory consumption and segmentation fault) via a crafted diff file.

GNU patch 2.7.1 allows remote attackers to write to arbitrary files via a symlink attack in a patch file.