SB2019020424 - Ubuntu update for linux
Published: February 4, 2019 Updated: October 31, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) NULL pointer dereference (CVE-ID: CVE-2018-1066)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote unauthenticated attacker to cause DoS condition on the target system.
The weakness exists in the fs/cifs/cifsencrypt.c:setup_ntlmv2_rsp() function due to NULL pointer dereference. A remote attacker can cause the service to crash.
2) Improper access control (CVE-ID: CVE-2018-17972)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to gain access to potentially sensitive information.
The vulnerability exists within the proc_pid_stack() function in fs/proc/base.c due to the Linux kernel does not ensure that only root may inspect the kernel stack of an arbitrary task. A local user can exploit racy stack unwinding and leak kernel task stack contents.
3) Improper access control (CVE-ID: CVE-2018-18281)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to bypass certain security restrictions.
The vulnerability exists due to improper access restrictions to memory when performing TLB flushes after dropping pagetable locks with mremap() syscall, A local user can access a physical page of a stale TLB entry after ftruncate() syscall is called to remove entries from the pagetables of a task that is in the middle of mremap() syscall.
Successful exploitation of the vulnerability may allow an attacker to gain access to sensitive information, stored in process memory.
4) Type Confusion (CVE-ID: CVE-2018-9568)
CWE-ID: CWE-843 - Type confusion
CVSSv4: 8.5 [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]
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a type confusion error in the sk_clone_lock() function in sock.c. A local user can run a specially crafted application to trigger memory corruption and execute arbitrary code on the target system with elevated privileges.
Remediation
Install update from vendor's website.