Scientific Linux Security Update : kernel on SL7.x x86_64 (Meltdown) (Spectre)

Medium Nessus Plugin ID 105535

Synopsis

The remote Scientific Linux host is missing one or more security updates.

Description

Security Fix(es) :

An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of instructions (a commonly used performance optimization). There are three primary variants of the issue which differ in the way the speculative execution can be exploited.

Note: This issue is present in hardware and cannot be fully fixed via software update. The updated kernel packages provide software mitigation for this hardware issue at a cost of potential performance penalty. The performance impact of these patches may vary considerably based on workload and hardware configuration.

In this update mitigations for x86-64 architecture are provided.

Variant CVE-2017-5753 triggers the speculative execution by performing a bounds-check bypass. It relies on the presence of a precisely-defined instruction sequence in the privileged code as well as the fact that memory accesses may cause allocation into the microprocessor's data cache even for speculatively executed instructions that never actually commit (retire). As a result, an unprivileged attacker could use this flaw to cross the syscall boundary and read privileged memory by conducting targeted cache side-channel attacks. (CVE-2017-5753, Important)

Variant CVE-2017-5715 triggers the speculative execution by utilizing branch target injection. It relies on the presence of a precisely-defined instruction sequence in the privileged code as well as the fact that memory accesses may cause allocation into the microprocessor's data cache even for speculatively executed instructions that never actually commit (retire). As a result, an unprivileged attacker could use this flaw to cross the syscall and guest/host boundaries and read privileged memory by conducting targeted cache side-channel attacks. (CVE-2017-5715, Important)

Variant CVE-2017-5754 relies on the fact that, on impacted microprocessors, during speculative execution of instruction permission faults, exception generation triggered by a faulting access is suppressed until the retirement of the whole instruction block. In a combination with the fact that memory accesses may populate the cache even when the block is being dropped and never committed (executed), an unprivileged local attacker could use this flaw to read privileged (kernel space) memory by conducting targeted cache side-channel attacks. (CVE-2017-5754, Important)

Note: CVE-2017-5754 affects Intel x86-64 microprocessors. AMD x86-64 microprocessors are not affected by this issue.

Solution

Update the affected packages.

See Also

http://www.nessus.org/u?31023846

Plugin Details

Severity: Medium

ID: 105535

File Name: sl_20180103_kernel_on_SL7_x.nasl

Version: 3.8

Type: local

Agent: unix

Published: 2018/01/04

Modified: 2018/05/25

Dependencies: 12634

Risk Information

Risk Factor: Medium

CVSS v2.0

Base Score: 4.7

Vector: CVSS2#AV:L/AC:M/Au:N/C:C/I:N/A:N

CVSS v3.0

Base Score: 5.6

Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Vulnerability Information

CPE: x-cpe:/o:fermilab:scientific_linux

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/RedHat/release, Host/RedHat/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2018/01/03

Exploitable With

CANVAS (CANVAS)

Reference Information

CVE: CVE-2017-5715, CVE-2017-5753, CVE-2017-5754

IAVA: 2018-A-0019, 2018-A-0020