SB2025061150 - Ubuntu update for amd64-microcode

Description

This security bulletin contains information about 3 vulnerabilities.

1) Input validation error (CVE-ID: CVE-2023-20584)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/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 validation of special address ranges with invalid device table entries (DTEs) in IOMMU. A local user can induce DTE faults to bypass RMP checks in SEV-SNP.

2) Incomplete cleanup (CVE-ID: CVE-2023-31356)

CWE-ID: CWE-459 - Incomplete cleanup

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/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 incomplete system memory cleanup in SEV firmware. A local privileged user can corrupt guest private memory.

3) Improper Verification of Cryptographic Signature (CVE-ID: CVE-2024-56161)

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/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 improper verification of cryptographic signature in AMD CPU ROM microcode patch loader. A local privileged user can load a malicious CPU microcode and escalate privileges on the system.

Remediation

Install update from vendor's website.

References

• https://ubuntu.com/security/notices/USN-7561-1