SB20260629119 - Ubuntu update for amd64-microcode

Description

This security bulletin contains information about 3 vulnerabilities.

1) Information exposure through microarchitectural state after transient execution (CVE-ID: CVE-2024-36350)

CWE-ID: CWE-1342 - Information Exposure through Microarchitectural State after Transient Execution

CVSSv4: CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to information leak. A local user can obtain sensitive data from previous stores.

2) Information exposure through microarchitectural state after transient execution (CVE-ID: CVE-2024-36357)

CWE-ID: CWE-1342 - Information Exposure through Microarchitectural State after Transient Execution

CVSSv4: CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to information leak. A local user can obtain sensitive data from the L1D cache.

3) Insufficient Entropy (CVE-ID: CVE-2025-62626)

CWE-ID: CWE-331 - Insufficient Entropy

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to insufficient entropy in Zen 5 processors, which causes the RDSEED instruction to return 0 at a rate inconsistent with randomness while incorrectly signaling success (CF=1), indicating a potential misclassification of failure as success. A local user can escalate privileges on the system.

Remediation

Install update from vendor's website.

References

• https://ubuntu.com/security/notices/USN-8475-1