SB2021101354 - SUSE update for the Linux Kernel
Published: October 13, 2021 Updated: June 28, 2025
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 17 secuirty vulnerabilities.
1) 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.
2) Cryptographic Issues (CVE-ID: CVE-2020-3702)
The vulnerability allows a remote attacker to gain access top sensitive information.
The vulnerability exists due to improper input validation in WIFI driver(Krook). A remote attacker can temporary disable WPA2 or the WPA/WPA2 mixed-mode encryption and intercept traffic in clear text.
3) Information disclosure (CVE-ID: CVE-2021-34556)
The vulnerability allows a local user to gain access to potentially sensitive information.
The vulnerability exists due to excessive data output by the application. A local user can gain unauthorized access to sensitive information on the system.
4) Observable discrepancy (CVE-ID: CVE-2021-35477)
The vulnerability allows a local user to gain access to sensitive information.
The vulnerability exists due to observable discrepancy error. A local user can gain access to sensitive information.
5) Security restrictions bypass (CVE-ID: CVE-2021-3653)
The vulnerability allows a malicious guest to escalate privileges on the system.
The vulnerability exists due to improperly imposed security restrictions within the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "int_ctl" field, this issue could allow a malicious L1 to enable AVIC support (Advanced Virtual Interrupt Controller) for the L2 guest.
As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.
6) Security restrictions bypass (CVE-ID: CVE-2021-3656)
The vulnerability allows a malicious guest to escalate privileges on the system.
The vulnerability exists due to improperly imposed security restrictions within the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "virt_ext" field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest.The vulnerability allows the L2 guest to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.
7) Resource exhaustion (CVE-ID: CVE-2021-3669)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to measuring usage of the shared memory does not scale with large shared memory segment counts. A local user can trigger resource exhaustion and perform a denial of service (DoS) attack.
8) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2021-3732)
The vulnerability allows a local user to gain access to sensitive information.
The vulnerability exists in the way the user mounts the TmpFS filesystem with OverlayFS. A local user can gain access to hidden files that should not be accessible.
9) NULL pointer dereference (CVE-ID: CVE-2021-3739)
The vulnerability allows a local user to read data or crash the application.
The vulnerability exists due to NULL pointer dereference within the btrfs_rm_device() function in fs/btrfs/volumes.c. A local user can read data or crash the application.
10) Out-of-bounds read (CVE-ID: CVE-2021-3743)
The vulnerability allows a local user to perform a denial of service attack.
The vulnerability exists due to a boundary condition in the Qualcomm IPC router protocol in the Linux kernel. A local user can gain access to out-of-bounds memory to leak internal kernel information or perform a denial of service attack.
11) Memory leak (CVE-ID: CVE-2021-3744)
The vulnerability allows a local user to perform DoS attack on the target system.
The vulnerability exists due memory leak in the ccp_run_aes_gcm_cmd() function in drivers/crypto/ccp/ccp-ops.c. A local user can force the application to leak memory and perform denial of service attack.
12) Use-after-free (CVE-ID: CVE-2021-3752)
The vulnerability allows a remote attacker to escalate privileges on the system.
The vulnerability exists due to a use-after-free error in the Linux kernel’s Bluetooth subsystem when a user calls connect to the socket and disconnect simultaneously. A local user can escalate privileges on the system.
13) Out-of-bounds read (CVE-ID: CVE-2021-3753)
The vulnerability allows a local user to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition in the vt_k_ioctl in drivers/tty/vt/vt_ioctl.c in the Linux kernel. A local user can trigger out-of-bounds read error and read contents of memory on the system.
14) Resource exhaustion (CVE-ID: CVE-2021-3759)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists in the Linux kernel’s ipc functionality of the memcg subsystem when user calls the semget function multiple times, creating semaphores. A local user can trigger resource exhaustion and perform a denial of service (DoS) attack.
15) Memory leak (CVE-ID: CVE-2021-3764)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to memory leak error in the ccp_run_aes_gcm_cmd() function in Linux kernel. A local user can trigger a memory leak error and perform a denial of service (DoS) attack.
16) Incorrect permission assignment for critical resource (CVE-ID: CVE-2021-38198)
The vulnerability allows a local user to perform a denial of service attack.The vulnerability exists due to arch/x86/kvm/mmu/paging_tmpl.h incorrectly computes the access permissions of a shadow page. A local user can trigger an error to perform a denial of service attack.
17) Race condition (CVE-ID: CVE-2021-40490)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a race condition in ext4_write_inline_data_end in fs/ext4/inline.c in the ext4 subsystem in the Linux kernel. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.
Remediation
Install update from vendor's website.