CVE-2025-20623: 
Linux Debian vulnerability analysis and mitigation

A microarchitectural vulnerability identified as CVE-2025-20623 affects Intel's 10th Generation Core processors. The vulnerability was disclosed on May 13, 2025, and involves exposure of sensitive information through shared microarchitectural predictor states that influence transient execution (NVD Database).

The vulnerability is characterized by a medium severity rating with a CVSS v4.0 base score of 5.7 and CVSS v3.1 base score of 5.6. The vulnerability requires local access and high attack complexity, with low privileges needed for exploitation. The CVSS vector string for v4.0 is CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N, indicating high confidentiality impact but no impact on integrity or availability (NVD Database).

The vulnerability allows for information disclosure through shared microarchitectural predictor states. When successfully exploited, it enables an authenticated user with local access to potentially expose sensitive information from the affected Intel processors (CVE Database).

Debian has released security updates addressing this vulnerability in their intel-microcode package. Fixed versions include 3.20250512.1~deb11u1 for bullseye and 3.20250512.1~deb12u1 for bookworm distributions (Debian Tracker).