SB2018053013 - Red Hat update for kernel
Published: May 30, 2018
Security Bulletin ID
SB2018053013
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
2
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Use-after-free error (CVE-ID: CVE-2017-18017)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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/E:U/U:Green
The vulnerability allows a remote attacker to cause DoS condition no the target system.
The weakness exists in the tcpmss_mangle_packet function in net/netfilter/xt_TCPMSS.c in the Linux kernel due to use-after-free error. A remote attacker can leverage the presence of xt_TCPMSS in an iptables action, trigger memory corruption and cause the system to crash.
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.