SB2018060816 - Amazon Linux AMI update for kernel
Published: June 8, 2018 Updated: June 12, 2018
Security Bulletin ID
SB2018060816
CSH Severity
High
Patch available
YES
Number of vulnerabilities
2
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Improper input validation (CVE-ID: CVE-2018-1120)
CWE-ID: CWE-20 - Improper input validation
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 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).
2) Speculative Store Bypass (CVE-ID: CVE-2018-3639)
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:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local attacker to obtain potentially sensitive information on the target system.
The weakness exists due to race conditions in CPU cache processing. A local attacker can conduct a side-channel attack to exploit a flaw in the speculative execution of Load and Store instructions to read privileged memory.
Note: the vulnerability is referred to as "Spectre variant 4".
Remediation
Install update from vendor's website.