SB2021110963 - Ubuntu update for linux

Description

This security bulletin contains information about 9 vulnerabilities.

1) Out-of-bounds read (CVE-ID: CVE-2019-19449)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

In the Linux kernel 5.0.21, mounting a crafted f2fs filesystem image can lead to slab-out-of-bounds read access in f2fs_build_segment_manager in fs/f2fs/segment.c, related to init_min_max_mtime in fs/f2fs/segment.c (because the second argument to get_seg_entry is not validated).

2) Improper Resource Shutdown or Release (CVE-ID: CVE-2020-36322)

CWE-ID: CWE-404 - Improper Resource Shutdown or Release

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists in the FUSE filesystem implementation in the Linux kernel due to fuse_do_getattr() calls make_bad_inode() in inappropriate situations. A local user can run a specially crafted program to trigger kernel crash.

Note, the vulnerability exists due to incomplete fix for #VU58207 (CVE-2021-28950).

3) Use-after-free (CVE-ID: CVE-2020-36385)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/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 a use-after-free error in drivers/infiniband/core/ucma.c, because the ctx is reached via the ctx_list in some ucma_migrate_id situations where ucma_close is called. A local user can run a specially crafted program to trigger the use-after-free error and execute arbitrary code with elevated privileges.

4) Missing initialization of resource (CVE-ID: CVE-2021-3655)

CWE-ID: CWE-909 - Missing initialization of resource

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to missing initialization of resource in the Linux kernel when processing inbound SCTP packets. A remote attacker can send specially crafted SCTP packets to the system and force the kernel to read uninitialized memory.

5) Out-of-bounds read (CVE-ID: CVE-2021-3743)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

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.

6) Out-of-bounds read (CVE-ID: CVE-2021-3753)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

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.

7) Resource exhaustion (CVE-ID: CVE-2021-3759)

CWE-ID: CWE-400 - Resource exhaustion

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

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.

8) Race condition (CVE-ID: CVE-2021-38199)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

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.

9) Out-of-bounds write (CVE-ID: CVE-2021-42252)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/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 execute arbitrary code.

The vulnerability exists due to an out-of-bounds write within the aspeed_lpc_ctrl_mmap() function in drivers/soc/aspeed/aspeed-lpc-ctrl.c. A local user can execute arbitrary code.

Remediation

Install update from vendor's website.

References

• https://ubuntu.com/security/notices/USN-5136-1