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Bug HP Networking

Critical Bug Last Year Allowed Bypassing Authentication On HPE ILO4 Servers With 29 'A' Characters (bleepingcomputer.com) 59

Public exploit code has been published for a severe vulnerability which last year affected Hewlett Packard Integrated Lights-Out 4 (HP iLO 4), a tool for remotely managing the company's servers.

HPE "silently released" patches last August, an anonymous reader reports, adding "details only emerged this spring after researchers started presenting their work at security conferences." The vulnerability is an authentication bypass that allows attackers access to HP iLO consoles. Researchers say this access can later be used to extract cleartext passwords, execute malicious code, and even replace iLO firmware. But besides being a remotely exploitable flaw, this vulnerability is also as easy as it gets when it comes to exploitation, requiring a cURL request and 29 letter "A" characters, as below:

curl -H "Connection: AAAAAAAAAAAAAAAAAAAAAAAAAAAAA"

Because of its simplicity and remote exploitation factor, the vulnerability — tracked as CVE-2017-12542 — received a severity score of 9.8 out of 10.

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Critical Bug Last Year Allowed Bypassing Authentication On HPE ILO4 Servers With 29 'A' Characters

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  • How can you extract cleartext passwords? Unless...finish this sentence...
    • by sjames ( 1099 ) on Saturday July 07, 2018 @08:58PM (#56908956) Homepage Journal

      They used a shellcode exploit to return the contents of a file on the ILO processor that has the passwords in cleartext! They didn't publish that as far as I can see, but there is a published python program to add a new user with admin privileges and a password of your choice.

      Bad HP! Go stand in the corner.

      Is it just me or have HP servers been a bit flaky for the last 5 years or so?

    • by Junta ( 36770 ) on Saturday July 07, 2018 @09:17PM (#56909030)

      The password is used directly as a shared secret for HMAC in IPMI. Therefore to support the ipmi protocol, the server must be able to know the plaintext of the password to a) prove to the client that they know the secret and b) to validate the HMAC sent by the client.

      Another potentially tricky one is SNMP. It's a shared secret, but at least you can localize the key. Of course it is localized to an snmp engine id, so while you may not directly have the cleartext password, you can spoof a matching snmp engine id to use the localized key as if you knew the password, at least to impersonate an snmp agent.

      Even on the TLS side of things, in practice things are not rosy because the vast majority of this class of devices have a self-signed cert, with all automation disabling cert validation and all users blindly clicked 'continue' at the warnings (there's no harsher message for "we have a conflicting stored cert" than "this is a self signed cert we haven't seen before")

      • Wow. Welcome to 1980.
        • by Junta ( 36770 )

          Interestingly enough, IPMI's current auth design was done in 2004. Somehow despite being at least two years after SNMP proved someone was thinking about how to derive a shared secret without using it directly.

          Somehow despite SRP being a well known thing that would neatly slot into IPMI, no one has bothered to amend the IPMI spec to remove the need for the server to know the password, and also to amend the poor decision for the server to send HMAC first.

  • by dgatwood ( 11270 ) on Saturday July 07, 2018 @09:08PM (#56908996) Homepage Journal

    ... when your network infrastructure was certified secure by the Fonz.

    Aaaaaaaaaaaaaaaaaaaay.

    • by Julz ( 9310 )

      Of course this has been fixed in [[Redfish]https://sourceforge.net/p/redfish-lab/wiki/Getting-started-with-the-iLO5-Redfish-API/] right?

      "redfish-lab
      Get started with the Redfish RESTful API from the DMTF
      Brought to you by: fdonze"

      Remove the "d" and you get "fonze". How's that for coincidence ;)

  • received a severity score of 9.8 out of 10

    What would be a ten? No authentication at all?

  • HP has been garbage since Carly Fiorino was running the place. Why anyone would do business with them at this point is beyond me.

  • This is great research! Have they tried "AAAAAAAAAAAAAAAAAAAAAAAAAAAAB" yet?

  • by cascadingstylesheet ( 140919 ) on Saturday July 07, 2018 @10:51PM (#56909326) Journal
    "Nobody would ever think to type 'A' 29 times!!
  • in NSA Got to collect on it all.
    The A ind DEA
    The A in other Agency.
    So safe even the buddy system contractors can use it.
  • Once I saw that the latest version is iLO 5, I figured it had to be vulnerable to the same exploit as iLO 4 and sure enough:

    https://support.hpe.com/hpsc/d... [hpe.com]

    "A security vulnerability in HPE Integrated Lights-Out 4, 5 (iLO 4 prior to v2.60, and iLO 5 prior to v1.30) could be remotely or locally exploited by an Administrative user to allow remote or local code execution."

  • If you're stupid enough to make your iLO connection directly publicly accessible and not secured behind a VPN or bastion server then you deserve to get pwned by whatever exploit comes your way. I will never understand why anyone would put an interface that is historically the weakest link out there where anyone can basically have console access to your hardware.

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