Vulnerability Monitor

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CVE-2023-39950


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.


Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.1, with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts integrity (unauthorized modifications), and limited availability for affected systems. Impacting 1 product from siemens organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2023, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2023-08-14T21:15:13.420

Last Modified

2024-11-21T08:16:05.920

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 6.1 (MEDIUM)

Weaknesses
  • Type: Secondary
    CWE-20

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application siemens efibootguard < 0.15 Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For siemens's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.