CVE Vulnerabilities

CVE-2019-13636

Improper Link Resolution Before File Access ('Link Following')

Published: Jul 17, 2019 | Modified: Nov 21, 2024
CVSS 3.x
5.9
MEDIUM
Source:
NVD
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS 2.x
5.8 MEDIUM
AV:N/AC:M/Au:N/C:N/I:P/A:P
RedHat/V2
RedHat/V3
5.9 MODERATE
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Ubuntu
MEDIUM

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.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Name Vendor Start Version End Version
Patch Gnu * 2.7.6 (including)
Red Hat Enterprise Linux 8 RedHat patch-0:2.7.6-11.el8 *
Patch Ubuntu bionic *
Patch Ubuntu devel *
Patch Ubuntu disco *
Patch Ubuntu trusty *
Patch Ubuntu trusty/esm *
Patch Ubuntu upstream *
Patch Ubuntu xenial *

Potential Mitigations

  • Follow the principle of least privilege when assigning access rights to entities in a software system.
  • Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

References