Debian Security Advisory

DSA-4735-1 grub2 -- security update

Date Reported:
29 Jul 2020
Affected Packages:
grub2
Vulnerable:
Yes
Security database references:
In Mitre's CVE dictionary: CVE-2020-10713, CVE-2020-14308, CVE-2020-14309, CVE-2020-14310, CVE-2020-14311, CVE-2020-15706, CVE-2020-15707.
More information:

Several vulnerabilities have been discovered in the GRUB2 bootloader.

  • CVE-2020-10713

    A flaw in the grub.cfg parsing code was found allowing to break UEFI Secure Boot and load arbitrary code. Details can be found at https://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/

  • CVE-2020-14308

    It was discovered that grub_malloc does not validate the allocation size allowing for arithmetic overflow and subsequently a heap-based buffer overflow.

  • CVE-2020-14309

    An integer overflow in grub_squash_read_symlink may lead to a heap based buffer overflow.

  • CVE-2020-14310

    An integer overflow in read_section_from_string may lead to a heap based buffer overflow.

  • CVE-2020-14311

    An integer overflow in grub_ext2_read_link may lead to a heap-based buffer overflow.

  • CVE-2020-15706

    script: Avoid a use-after-free when redefining a function during execution.

  • CVE-2020-15707

    An integer overflow flaw was found in the initrd size handling.

Further detailed information can be found at https://www.debian.org/security/2020-GRUB-UEFI-SecureBoot

For the stable distribution (buster), these problems have been fixed in version 2.02+dfsg1-20+deb10u1.

We recommend that you upgrade your grub2 packages.

For the detailed security status of grub2 please refer to its security tracker page at: https://security-tracker.debian.org/tracker/grub2