CVE Vulnerabilities

CVE-2020-11446

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

Published: Apr 29, 2020 | Modified: Jul 21, 2021
CVSS 3.x
7.8
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
4.6 MEDIUM
AV:L/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

ESET Antivirus and Antispyware Module module 1553 through 1560 allows a user with limited access rights to create hard links in some ESET directories and then force the product to write through these links into files that would normally not be write-able by the user, thus achieving privilege escalation.

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
Antivirus_and_antispyware Eset 1553 (including) 1560 (including)
Endpoint_antivirus Eset - (including) - (including)
Endpoint_security Eset - (including) - (including)
File_security Eset - (including) - (including)
Internet_security Eset - (including) - (including)
Mail_security Eset - (including) - (including)
Nod32_antivirus Eset - (including) - (including)
Smart_security Eset - (including) - (including)

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