SB2020070615 - Ubuntu update for linux
Published: July 6, 2020 Updated: April 23, 2025
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 secuirty vulnerabilities.
1) NULL pointer dereference (CVE-ID: CVE-2020-10711)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in the Linux kernel's SELinux subsystem when importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated.
A remote attacker can send specially crafted packets the affected system, trigger a NULL pointer dereference error and crash the Linux kernel.
2) Input validation error (CVE-ID: CVE-2020-12770)
The vulnerability allows a local user to execute arbitrary code on the system.
The vulnerability exists due to the "sg_write" lacks an "sg_remove_request" call in a certain failure case. A local user can pass specially crafted input to the application and execute arbitrary code on the target system.
3) Out-of-bounds read (CVE-ID: CVE-2020-13143)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a boundary condition in "gadget_dev_desc_UDC_store" in "drivers/usb/gadget/configfs.c" file. A remote attacker can trigger out-of-bounds read error and cause a denial of service on the target system.
4) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2020-10751)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due in the Linux kernels SELinux LSM hook implementation where the kernel incorrectly assumed that an skb would only contain a single netlink message. The hook would incorrectly only validate the first netlink message in the skb and allow or deny the rest of the messages within the skb with the granted permission without further processing.
Remediation
Install update from vendor's website.