CVE-2019-20633
LowSummary
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.
Risk Assessment
An attacker can exploit this vulnerability to crash the patch process, potentially disrupting systems that rely on automated patching.
Recommendation
It is recommended to upgrade GNU patch to version 2.7.6 or later, which includes a complete fix for this issue.
Other vulnerabilities in GNU patch
See all- CVE-2015-1395High
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.
- CVE-2026-56289Medium
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.
- CVE-2026-56288Medium
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.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS