CVE-2023-39950

NameCVE-2023-39950
Descriptionefibootguard 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs1049436

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
efibootguard (PTS)bookworm0.13-2+deb12u1fixed
sid, trixie0.16-2fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
efibootguardsourcebookworm0.13-2+deb12u1
efibootguardsource(unstable)0.15-11049436

Notes

https://github.com/siemens/efibootguard/commit/965d65c5751898c4bb094ef191b7387819423414 (v0.15)
https://github.com/siemens/efibootguard/commit/53dee61dc8b3a83c882e4bc9a0cfe7d6d73610c4 (v0.15)

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