Debian Security Advisory
DSA-4735-1 grub2 -- security update
- Date Reported:
- 29 Jul 2020
- Affected Packages:
- 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.
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/
It was discovered that grub_malloc does not validate the allocation size allowing for arithmetic overflow and subsequently a heap-based buffer overflow.
An integer overflow in grub_squash_read_symlink may lead to a heap based buffer overflow.
An integer overflow in read_section_from_string may lead to a heap based buffer overflow.
An integer overflow in grub_ext2_read_link may lead to a heap-based buffer overflow.
script: Avoid a use-after-free when redefining a function during execution.
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