SB2017121501 - Ubuntu update for Linux kernel
Published: December 15, 2017
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) Use-after-free error (CVE-ID: CVE-2017-16939)
CWE-ID: CWE-416 - Use After Free
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:P/U:Clear
The vulnerability allows a local attacker to cause DoS condition on the target system.
The weakness exists in the XFRM dump policy implementation in net/xfrm/xfrm_user.c in the Linux kernel due to use-after-free error. A local attacker can make a specially crafted SO_RCVBUF setsockopt system call in conjunction with XFRM_MSG_GETPOLICY Netlink messages, trigger memory corruption and cause the service to crash.
Successful exploitation of the vulnerability results in denial of service.
2) Race condition (CVE-ID: CVE-2017-1000405)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
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:P/U:Clear
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to a race condition within touch_pmd() function in mmhugemem.c file when handling THPs. A local user can read read-only huge pages using the get_user_pages() function and overwrite arbitrary huge pages and files mapped via THP.
Successful exploitation of the vulnerability may allow an attacker to perform a denial of service (DoS) attack.
This vulnerability is a result of patch against a another privilege escalation vulnerability in Linux kernel known as Dirty Cow (CVE-2016-5195).
3) NULL pointer derefenrece (CVE-ID: CVE-2017-12193)
CWE-ID: CWE-476 - NULL Pointer Dereference
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 assoc_array implementation in which a new leaf is added that needs to go into a node that happens to be full. A local user can trigger NULL pointer dereference error and crash the kernel.
4) Out-of-bounds read (CVE-ID: CVE-2017-16643)
CWE-ID: CWE-125 - Out-of-bounds read
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 attacker to cause DoS condition on the target system.
The weakness exists due to out-of-bounds read in the parse_hid_report_descriptor function in drivers/input/tablet/gtco.c in the Linux kernel. A local attacker can use a specially crafted USB device and cause the service to crash.
Successful exploitation of the vulnerability results in denial of service.
Remediation
Install update from vendor's website.