CVE-2021-45261

A double-free exists in the another_hunk function in pch.c in GNU patch through 2.7.6. It can be triggered while processing a specially crafted patch 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.

In GNU patch through version 2.7.6, there is a double free vulnerability in the another_hunk function in pch.c, which can cause a denial of service via a crafted patch file. This issue exists because of an incomplete fix for CVE-2018-6952.

A flaw was found in GNU patch. An attacker can achieve arbitrary file creation outside the intended working directory by enticing a user or automated workflow to apply a specially crafted patch file. Due to missing validation during automatic patch reversal, absolute file paths in patch headers are accepted rather than rejected. Consequently, the utility can create files in arbitrary locations with the permissions of the executing user.

GNU Patch is vulnerable to a denial of service (DoS) due to improper validation of hunk line offsets in unified-diff input. A specially crafted patch can specify an extremely large line number, causing an infinite processing loop and excessive CPU consumption.

GNU patch is vulnerable to a NULL pointer dereference when processing a specially crafted unified-diff patch file. Improper handling of consecutive end-of-file newline markers can corrupt internal hunk data structures, causing the application to pass a NULL pointer to fwrite() during patch processing.