BSA-2022-2012

Brocade Fabric OS

2 more products

21278

25 July 2022

25 July 2022

Closed

Low

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - 3.3

N/A

CVE-2021-27798

Summary

Security Advisory ID : BSA-2022-2012

Component : Brocade Fabric OS

Revision : 1.1: Final

Brocade has received a report from Black Lantern Security of a potential Privileged Directory Traversal vulnerability on Brocade Fabric OS: v7.4.1b, v7.3.1d stating that:

“From within the restricted shell environment (rbash) as either the “user” or “factory” account, it is possible to access and list the entirety of the filesystem utilizing the “more” binary and tab-completion.

This appears to be with root equivalent permissions regardless of who you are logged in as”.

The detail provided by the Researcher.

  • From within the restricted shell environment (rbash) as either the “user” or “factory” account, it is possible to access and list the entirety of the filesystem utilizing the “more” binary and tab-completion. This appears to be with root equivalent permissions regardless of who you are logged in as.
  • To reproduce, in an active SSH session with the affected software, type the command “more” and press the TAB key until a listing of the current directory is given. Supplying partial paths such as “more /” or “more /etc/” followed by pressing the TAB key will display that directories full contents.
  • An attacker gains complete knowledge of the underlying filesystem structure including all available binaries within the user’s PATH environment variable.

Brocade's statement

Brocade Fabric OS: v7.4.1b and v7.3.1d have reached End of Availability (EOA) and are no longer supported. Brocade recommends Customers run supported Brocade software versions.

  • Brocade Fabric OS Administration Guide documents default users accounts for Brocade Fabric OS actively supported versions.
  • The Brocade Fabric OS Administration Guide reads: “predefined accounts offered by Fabric OS that are available in the local-switch user database. The password for all default accounts should be changed during the initial installation and configuration of each switch.”
  • In all actively supported Brocade Fabric OS versions, users cannot move beyond file systems permission assigned to them; the switch admin can also restrict user access to the switch.
  • In Brocade Fabric OS 9. x, released June 24th, 2020, Brocade has made architectural changes to prevent using <tab> <tab>.
  • Customers are advised to refer to the Brocade Product End-of-Life report.

Credit

This issue was found by “Cody Martin” from Black Lantern Security on Brocade Fabric OS: v7.4.1b, and v7.3.1d.

Revision History

VersionChangeDate
1.0Initial PublicationJul 25, 2022

1.1

Add EOL link.

Aug 1, 2022