CVE-2023-40550: Shim: out-of-bound read in verify_buffer_sbat()
An out-of-bounds read flaw was found in Shim when it tried to validate the SBAT information. This issue may expose sensitive data during the system's boot phase.
Other sources
rhboot shim could allow a remote authenticated attacker to obtain sensitive information, caused by an out-of-bound read flaw in the verifybuffersbat() function. By sending a specially crafted request, an attacker could exploit this vulnerability to obtain sensitive information, and use this information to launch further attacks against the affected system.
— IBM
There's an out of bound read in shim at verifybuffersbat() function, which can lead to information disclosure.
— Red Hat
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2023-40550?
CVE-2023-40550 is classified as an out-of-bounds read vulnerability potentially leading to information disclosure.
How do I fix CVE-2023-40550?
To fix CVE-2023-40550, update the Shim package to version 15.8 or later.
Which software is affected by CVE-2023-40550?
CVE-2023-40550 affects the Shim package versions up to 15.8, and specific versions of Fedora and Red Hat Enterprise Linux.
What type of attack can exploit CVE-2023-40550?
CVE-2023-40550 may be exploited during the system's boot phase to expose sensitive data.
Is there a workaround for CVE-2023-40550?
Currently, there are no documented workarounds for CVE-2023-40550; applying the patch is recommended.