QID 198521

Date Published: 2021-10-06

QID 198521: Ubuntu Security Notification for Linux kernel (Raspberry Pi) Vulnerabilities (USN-5091-2)

The bpf verifier in the linux kernel missed possible mispredicted branches due to type confusion, allowing a side-channel attack.
The tracing subsystem in the linux kernel did not properly keep track of per-cpu ring buffer state.
The virtio console implementation in the linux kernel did not properly validate input lengths in some situations.
The nfsv4 client implementation in the linux kernel did not properly order connection setup operations.
The max-3421 host usb device driver in the linux kernel did not properly handle device removal events.

Note: The preceding description block is extracted directly from the security advisory. Using automation, we have attempted to clean and format it as much as possible without introducing additional issues.

an attacker could use this to expose sensitive information.
(cve-2021-33624).
A privileged attacker could use this to cause a denial of service. (
Cve-2021-3679).
A local attacker could possibly use this to cause a denial of service (system crash) (cve-2021-38160).
An attacker controlling a remote nfs server could use this to cause a denial of service on the client. (
Cve-2021-38199).
A physically proximate attacker could use this to cause a denial of service (system crash) (cve-2021-38204).

  • CVSS V3 rated as High - 7.8 severity.
  • CVSS V2 rated as High - 7.2 severity.
  • Solution
    Refer to Ubuntu advisory: USN-5091-2 for affected packages and patching details, or update with your package manager.
    Vendor References
    Software Advisories
    Advisory ID Software Component Link
    USN-5091-2 Ubuntu Linux URL Logo ubuntu.com/security/notices/USN-5091-2