[Full-disclosure] Supermicro IPMI: backup function causes password to be stored at public web location

[Floris Bos <bos@xxxxxxxxxxxxxxxxxx>]

==
Product
==

Tested hardware: 

Supermicro X8SI6-F mainboard - IPMI firmware: 2.50
Supermicro X9SCL-F mainboard - IPMI firmware: 1.01

Likely affects other Supermicro boards of those generations that use the
same type of firmware.

==
Problem
==

Modern servers often include a feature called IPMI to remotely manage and
monitor the server.
Since setting up the IPMI card properly requires entering a dozen settings
ranging from network information, usernames and passwords, 
to e-mail address that should be notified if a hardware failure occurs,
most IPMI cards offer a convenience function to backup and restore the
settings to a file.


In the case of these boards you can login to the IPMI webinterface and go
to "maintenance" -> "IPMI configuration" -> "save IPMI configuration" and a
configuration backup file is generated.

This file is then available for download at:
http://ipmi-ip-address/save_config.bin

The problem is that this file is PUBLICLY accessible to everyone, even
those NOT logged into the webinterface.
Furtermore the file remains accessible until the server chassis loses
power, which is unlikely to be anytime soon if the server is already racked
up in a datacenter.

Given that the configuration file contains the IPMI administrator password
in plain-text, this poses a security risk if you are using public
IP-addresses for IPMI.
An attacker could scan the IP-range of a large colocation provider for the
file "/save_config.bin", and retrieve the login details of every server on
which the "save IPMI configuration" feature was used since the last power
failure.

==
Workarounds
==

- Do not use the configuration backup function. If you have done so in the
past, change your IPMI passwords.
- Use private IPs for IPMI



Vendor was notified on 3 May 2011.


Yours sincerely,

Floris Bos

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