SB2018070228 - Ubuntu update for linux, linux-aws, linux-azure and more
Published: July 2, 2018 Updated: October 31, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 6 vulnerabilities.
1) NULL pointer dereference (CVE-ID: CVE-2018-1094)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: 6.8 [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]
The vulnerability allows a local attacker to cause DoS condition on the target system.
The weakness exists due to improper initialization of the crc32c checksum driver when using the ext4_fill_super function, as defined in the fs/ext4/super.c source code file. A local attacker can mount a customized ext4 image, trigger NULL pointer dereference in the ext4/xattr.c:ext4_xattr_inode_hash() function and cause the service to crash.
2) Information disclosure (CVE-ID: CVE-2018-10940)
CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local attacker to obtain potentially sensitive information.
The vulnerability exists in the cdrom_ioctl_media_changed function due to incorrect bounds check in the CDROM driver CDROM_MEDIA_CHANGED IOCTL. A local attacker can execute a file or program that submits malicious input to the targeted system, trigger memory corruption and access sensitive kernel information, which could be used to conduct further attacks.
3) NULL pointer dereference (CVE-ID: CVE-2018-1095)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote authenticated attacker to cause DoS condition on the target system.
The weakness exists in the ext4_xattr_check_entries function in fs/ext4/xattr.c due to improper validation of xattr sizes, which causes misinterpretation of a size as an error code. A remote attacker can submit a specially crafted ext4 image, trigger NULL pointer dereference and cause the service to crash.
4) NULL pointer dereference (CVE-ID: CVE-2018-1095)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: 6.8 [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]
The vulnerability allows a local attacker to cause DoS condition on the target system.
The weakness exists due to improper validation of xattr sizes when using the ext4_xattr_check_entries function, as defined in the fs/ext4/super.c source code file. A local attacker can mount a malicious ext4 image, trigger NULL pointer dereference in the fs/posix_acl.c:get_acl() function and cause the service to crash.
5) Information disclosure (CVE-ID: CVE-2018-11508)
CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local attacker to obtain potentially sensitive information.
The vulnerability exists in the compat_get_timex function, as defined in the kernel/compat.c source code file due to an uninitialized struct field in compat adjtimex system calls. A local attacker can send a compat adjtimex system call that submits malicious input and access sensitive kernel memory content, which could be used to conduct further attacks.
6) Security restrictions bypass (CVE-ID: CVE-2018-7755)
CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls
CVSSv4: 5.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local unauthenticated attacker to bypass security restrictions on the target system.
The weakness exists in the drivers/block/floppy.c source code in the fd_locked_ioctl function due to insufficient security restrictions. A local attacker can bypass security restrictions through the system floppy drive and obtain kernel code and data from the system.
Remediation
Install update from vendor's website.