Security Bulletin
Summary
An attacker with access to the host could send malformed commands to the TPM which would result in a TPM DoS. A complete power cycle of the system is required to recover.
Vulnerability Details
CVEID: CVE-2023-1017
DESCRIPTION: Trusted Computing Group Trusted Platform Module could allow a local authenticated attacker to execute arbitrary code on the system, caused by an out-of-bounds write flaw in the CryptParameterDecryption routine. By sending a specially crafted request, an attacker could exploit this vulnerability to execute arbitrary code in the TPM context or crash the TPM chip/process or rendering it unusable.
CVSS Base score: 7.8
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/248634 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2023-1018
DESCRIPTION: Trusted Computing Group Trusted Platform Module could allow a local authenticated attacker to obtain sensitive information, caused by an out-of-bounds read in the CryptParameterDecryption routine. By sending a specially crafted request, an attacker could exploit this vulnerability to read or access sensitive data stored in the TPM.
CVSS Base score: 5.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/248636 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| Host firmware | OP940.00 - OP940.60 |
Remediation/Fixes
Customers with the products below should install OP940.70 or newer to remediate this vulnerability.
Power 9
1) IBM Power System AC922 (8335-GTG, 8335-GTX)
When the FW listed above has been installed there are additional configuration options available to enable you to completely disable the TPM to avoid any possible malicious entity from performing the attack described. To complete the mitigation of this attack follow these instructions:
Login as root to the target BMC:
Set TPMEnable (aka TPM required) to false
busctl set-property xyz.openbmc_project.Settings /xyz/openbmc_project/control/host0/TPMEnable xyz.openbmc_project.Control.TPM.Policy TPMEnable b false
Set TPMDisable to true
busctl set-property xyz.openbmc_project.Settings /xyz/openbmc_project/control/host0/TPMDisable xyz.openbmc_project.Control.TPM.Policy TPMDisable b true
To validate both sensors are set correctly:
busctl get-property xyz.openbmc_project.Settings /xyz/openbmc_project/control/host0/TPMEnable xyz.openbmc_project.Control.TPM.Policy TPMEnable
busctl get-property xyz.openbmc_project.Settings /xyz/openbmc_project/control/host0/TPMDisable xyz.openbmc_project.Control.TPM.Policy TPMDisable
You will also see the following from the console when it is disabled:
No TPM chip found, activating TPM-bypass!
Workarounds and Mitigations
Limit access to run arbitrary commands to the TPM.
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
01 Aug 2024: Initial Publication
*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.
Disclaimer
According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.
Document Location
Worldwide
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Document Information
Modified date:
01 August 2024
UID
ibm17161931