efibootguard up to 0.14 bg_printenv memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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5.1$0-$5k0.00

A vulnerability has been found in efibootguard up to 0.14 and classified as critical. Affected by this vulnerability is the function bg_printenv. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

efibootguard 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.

The weakness was published 08/15/2023 as GHSA-j6pp-7g99-24m7. The advisory is shared at github.com. This vulnerability is known as CVE-2023-39950 since 08/07/2023. Technical details are known, but no exploit is available.

Upgrading to version 0.15 eliminates this vulnerability.

Productinfo

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Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.2
VulDB Meta Temp Score: 5.1

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.2
NVD Vector: 🔍

CNA Base Score: 6.1
CNA Vector (GitHub, Inc.): 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: efibootguard 0.15

Timelineinfo

08/07/2023 🔍
08/15/2023 +8 days 🔍
08/15/2023 +0 days 🔍
09/09/2023 +25 days 🔍

Sourcesinfo

Advisory: GHSA-j6pp-7g99-24m7
Status: Confirmed

CVE: CVE-2023-39950 (🔍)

Entryinfo

Created: 08/15/2023 09:30 AM
Updated: 09/09/2023 09:33 AM
Changes: 08/15/2023 09:30 AM (50), 09/09/2023 09:33 AM (9)
Complete: 🔍
Cache ID: 18:7E7:40

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