CVE-2023-39950

Insufficient input validation in efibootguard

Description

efibootguard is a simple UEFI boot loader with support for safely switching between current and updated partition sets. Insufficient or missing validation and sanitization of input from untrustworthy bootloader environment files can cause crashes and probably also code injections into `bg_setenv`) or programs using `libebgenv`. This is triggered when the affected components try to modify a manipulated environment, in particular its user variables. Furthermore, `bg_printenv` may crash over invalid read accesses or report invalid results. Not affected by this issue is EFI Boot Guard's bootloader EFI binary. EFI Boot Guard release v0.15 contains required patches to sanitize and validate the bootloader environment prior to processing it in userspace. Its library and tools should be updated, so should programs statically linked against it. An update of the bootloader EFI executable is not required. The only way to prevent the issue with an unpatched EFI Boot Guard version is to avoid accesses to user variables, specifically modifications to them.

Category

6.1
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.07%
Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory github.com
Affected: siemens efibootguard
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2023-39950?
CVE-2023-39950 has been scored as a medium severity vulnerability.
How to fix CVE-2023-39950?
To fix CVE-2023-39950, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2023-39950 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-39950 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-39950?
CVE-2023-39950 affects siemens efibootguard.
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