CVE-2020-27779 — Improper Authorization in Grub2

CWE-285 — Improper Authorization8 documents8 sources
Severity
7.5HIGHNVD
EPSS
0.0%
top 96.52%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
7
GNU Grub2Fedoraproject FedoraRedhat Enterprise Linux+4 more
Timeline
PublishedMar 3
Latest updateMay 24

Description

A flaw was found in grub2 in versions prior to 2.06. The cutmem command does not honor secure boot locking allowing an privileged attacker to remove address ranges from memory creating an opportunity to circumvent SecureBoot protections after proper triage about grub's memory layout. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:HExploitability: 0.8 | Impact: 6.0

Affected Packages4 packages

▶NVDgnu/grub2< 2.06
▶Debiangnu/grub2< 2.04-16+3
▶CVEListV5gnu/grub2grub 2.06

Also affects: Fedora 33, 34, Enterprise Linux 7.0, 8.0, 7.2, 7.3, 7.4, 7.6, 7.7, 8.2, 8.1

🔴Vulnerability Details

3
GHSA
GHSA-7p29-8vr2-rmvx: A flaw was found in grub2 in versions prior to 2↗2022-05-24
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CVEList
CVE-2020-27779: A flaw was found in grub2 in versions prior to 2↗2021-03-03
▶
OSV
CVE-2020-27779: A flaw was found in grub2 in versions prior to 2↗2021-03-03
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📋Vendor Advisories

4
Ubuntu
GRUB 2 vulnerabilities↗2021-06-18
▶
Microsoft
A flaw was found in grub2 in versions prior to 2.06. The cutmem command does not honor secure boot locking allowing an privileged attacker to remove address ranges from memory creating an opportunity ↗2021-03-09
▶
Red Hat
grub2: cutmem command allows privileged user to remove memory regions when Secure Boot is enabled↗2021-03-02
▶
Debian
CVE-2020-27779: grub2 - A flaw was found in grub2 in versions prior to 2.06. The cutmem command does not...↗2020
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CVE-2020-27779 — Improper Authorization in GNU Grub2 | cvebase