SB2019031518 - Ubuntu update for linux, linux-aws, linux-kvm and more
Published: March 15, 2019 Updated: October 31, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 5 vulnerabilities.
1) NULL pointer dereference (CVE-ID: CVE-2017-18241)
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 in the fs/f2fs/segment.c source code file due to the use of the noflush_merge option, which could trigger a NULL value for a flush_cmd_control data structure. A local attacker can trigger NULL pointer dereference and kernel panic and cause the service to crash.
2) Improper input validation (CVE-ID: CVE-2018-1120)
CWE-ID: CWE-20 - Improper input validation
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 user to cause DoS condition on the target system.
The weakness exists due to insufficient validation of user-supplied input. A local user can block any read() access to /proc/PID/cmdline by mmap()ing a FUSE file (Filesystem in Userspace) onto this process's command-line arguments, block pgrep, pidof, pkill, ps, and w, either forever (a denial of service), or for some controlled time (a synchronization tool for exploiting other vulnerabilities).
3) Out-of-bounds read (CVE-ID: CVE-2018-19985)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 2.4 [CVSS:4.0/AV:P/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 user to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition when the function "hso_get_config_data" in "drivers/net/usb/hso.c" reads "if_num" from the USB device (as a u8) and uses it to index a small array. An authenticated local user with physical access to the system can use a malicious USB, trigger out-of-bounds read error and read contents of memory on the system.
4) Memory corruption (CVE-ID: CVE-2018-7740)
CWE-ID: CWE-119 - Memory corruption
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 no the target system.
The weakness exists in the resv_map_release function due to boundary error when handling user-supplied input. A local attacker can execute an application that submits malicious input, trigger memory corruption and cause the system to crash.
5) Security restrictions bypass (CVE-ID: CVE-2019-6133)
CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to bypass security restrictions on the target system.
The vulnerability exists due to fork() is not atomic, and therefore authorization decisions are improperly cached, related to lack of uid checking in polkitbackend/polkitbackendinteractiveauthority.c. A remote unauthenticated attacker can bypass the "start time" protection mechanism
Remediation
Install update from vendor's website.