CVE Vulnerabilities

CVE-2021-23772

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

Published: Dec 24, 2021 | Modified: Jan 04, 2022
CVSS 3.x
8.8
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
6.8 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

This affects all versions of package github.com/kataras/iris; all versions of package github.com/kataras/iris/v12. The unsafe handling of file names during upload using UploadFormFiles method may enable attackers to write to arbitrary locations outside the designated target folder.

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
Iris Iris-go * 12.1.8
Iris Iris-go 12.2.0 12.2.0
Iris Iris-go 12.2.0 12.2.0
Iris Iris-go 12.2.0 12.2.0
Iris Iris-go 12.2.0 12.2.0
Iris Iris-go 12.2.0 12.2.0

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