CVE Vulnerabilities

CVE-2016-10374

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

Published: May 17, 2017 | Modified: Mar 02, 2020
CVSS 3.x
5.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
CVSS 2.x
2.1 LOW
AV:L/AC:L/Au:N/C:N/I:P/A:N
RedHat/V2
RedHat/V3
2.8 LOW
CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
Ubuntu
LOW

perltidy through 20160302, as used by perlcritic, check-all-the-things, and other software, relies on the current working directory for certain output files and does not have a symlink-attack protection mechanism, which allows local users to overwrite arbitrary files by creating a symlink, as demonstrated by creating a perltidy.ERR symlink that the victim cannot delete.

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
Perltidy Perltidy_project * 2016-03-02 (including)
Perltidy Ubuntu artful *
Perltidy Ubuntu esm-apps/xenial *
Perltidy Ubuntu trusty *
Perltidy Ubuntu upstream *
Perltidy Ubuntu xenial *
Perltidy Ubuntu yakkety *
Perltidy Ubuntu zesty *

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