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CVE-2020-27749

MEDIUMCVSS 6.7/10EPSS 0.57%

Last modified

CVE-2020-27749 is a medium-severity vulnerability rated 6.7/10 on the CVSS scale. A flaw was found in grub2 in versions prior to 2.06. Variable names present are expanded in the supplied command line into their corresponding variable contents, using a 1kB stack buffer for temporary storage, without sufficient bounds checking. EPSS estimates a 0.57% chance of exploitation in the next 30 days.

Description

A flaw was found in grub2 in versions prior to 2.06. Variable names present are expanded in the supplied command line into their corresponding variable contents, using a 1kB stack buffer for temporary storage, without sufficient bounds checking. If the function is called with a command line that references a variable with a sufficiently large payload, it is possible to overflow the stack buffer, corrupt the stack frame and control execution which could also circumvent Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Metrics

CVSS 3.1
6.7/10

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.57%

42.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
GnuGrub2< 2.06
RedhatEnterprise Linux7.0
RedhatEnterprise Linux8.0
RedhatEnterprise Linux Server Aus7.2
RedhatEnterprise Linux Server Aus7.3
RedhatEnterprise Linux Server Aus7.4
RedhatEnterprise Linux Server Aus7.6
RedhatEnterprise Linux Server Aus7.7
RedhatEnterprise Linux Server Aus8.2
RedhatEnterprise Linux Server Eus7.6
RedhatEnterprise Linux Server Eus7.7
RedhatEnterprise Linux Server Eus8.1
RedhatEnterprise Linux Server Tus7.4
RedhatEnterprise Linux Server Tus7.6
RedhatEnterprise Linux Server Tus7.7
RedhatEnterprise Linux Server Tus8.2
RedhatEnterprise Linux Workstation7.0
FedoraprojectFedora33
FedoraprojectFedora34
NetappOntap Select Deploy Administration UtilityAll versions

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2020-27749?
A flaw was found in grub2 in versions prior to 2.06. Variable names present are expanded in the supplied command line into their corresponding variable contents, using a 1kB stack buffer for temporary storage, without sufficient bounds checking. If the function is called with a command line that references a variable with a sufficiently large payload, it is possible to overflow the stack buffer, corrupt the stack frame and control execution which could also circumvent Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
How severe is CVE-2020-27749?
CVE-2020-27749 has a CVSS score of 6.7/10 (MEDIUM severity). The EPSS model estimates a 0.57% probability of exploitation in the next 30 days.
How do I fix CVE-2020-27749?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-27749?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST