SB2021093043 - Ubuntu update for linux-raspi
Published: September 30, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 secuirty vulnerabilities.
1) Type Confusion (CVE-ID: CVE-2021-33624)
The vulnerability allows a local user to gain access to sensitive information.
The vulnerability exists due to a type confusion error within kernel/bpf/verifier.c in the Linux kernel. A an unprivileged BPF program can read arbitrary memory locations via a side-channel attack.
2) Resource exhaustion (CVE-ID: CVE-2021-3679)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to lack of CPU resource in the Linux kernel tracing module functionality when using trace ring buffer in a specific way. A privileged local user (with CAP_SYS_ADMIN capability) could use this flaw to starve the resources causing denial of service.
3) Race condition (CVE-ID: CVE-2021-38199)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to fs/nfs/nfs4client.c in the Linux kernel has incorrect connection-setup ordering. A remote attacker with access to a remote NFSv4 server can perform a denial of service (DoS) attack by arranging the server to be unreachable during trunking detection.
4) Use-after-free (CVE-ID: CVE-2021-38204)
The vulnerability allows a local attacker to perform a denial of service attack.
The vulnerability exists due to a use-after-free error in the drivers/usb/host/max3421-hcd.c in the Linux kernel. An attacker with physical access to the system can remove a MAX-3421 USB device to perform a denial of service attack.
Remediation
Install update from vendor's website.