A vulnerability has been discovered in certain HP PC BIOS, which could allow for local arbitrary code execution. The BIOS is a firmware which is used to provide runtime services for operating systems and programs and to perform hardware initialization during the booting process. Successful exploitation of this vulnerability could allow for local arbitrary code execution with kernel level privileges. An attacker could then install programs; view; change, or delete data; or create new accounts with full user rights.
THREAT INTELLIGENCE: A proof-of-concept writeup was posted to GitHub on May 10, 2022. However, there are no reports of active exploitation of the vulnerability.
SYSTEMS AFFECTED:
- This vulnerability is found in the BIOS of numerous HP systems. For a full list of affected systems and BIOS versions please visit: https://learn.cisecurity.org/e/799323/6184733-6184761-16-hpsbhf03788/241jb2/315378526?h=90QfMktP4fc2o_j5pz_GJRMUIjvin2egbCFNlkOlMGk
RISK:
Government:
- Large and medium government entities: High
- Small government entities: High
Businesses:
- Large and medium business entities: High
- Small business entities: High
Home users: Low
TECHNICAL SUMMARY:
A vulnerability has been discovered in certain HP PC BIOS, which could allow for local arbitrary code execution. The BIOS is a firmware which is used to provide runtime services for operating systems and programs and to perform hardware initialization during the booting process. This vulnerability is exploited by taking advantage of System Management Interrupt Handler (SMI Handler)’s functionality to execute code from overwritten memory. The CVEs associated with this vulnerability are: CVE-2021-3808 and CVE-2021-3809 Successful exploitation of this vulnerability could allow for local arbitrary code execution with kernel level privileges. An attacker could then install programs; view; change, or delete data; or create new accounts with full user rights.
RECOMMENDATIONS:
We recommend the following actions be taken:
- Upgrade to the latest version of the BIOS for systems affected.
- Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.
Verify no unauthorized system modifications have occurred on the system before applying the patch.
REFERENCES:
CVE: https://www.cve.org/CVERecord?id=CVE-2021-3808
https://www.cve.org/CVERecord?id=CVE-2021-3809
HP:https://support.hp.com/us-en/document/ish_6184733-6184761-16/hpsbhf03788
nStarke:https://nstarke.github.io/uefi/smm/2022/05/10/smm-callout-in-hp-products.html