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amazonAmazonALAS2-2018-1038
HistoryJun 08, 2018 - 6:08 p.m.

Important: kernel

2018-06-0818:08:00
alas.aws.amazon.com
26

4.7 Medium

CVSS2

Attack Vector

LOCAL

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

NONE

Availability Impact

NONE

AV:L/AC:M/Au:N/C:C/I:N/A:N

5.6 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

6.9 Medium

AI Score

Confidence

High

0.003 Low

EPSS

Percentile

65.2%

Issue Overview:

An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of Load & Store instructions (a commonly used performance optimization). It relies on the presence of a precisely-defined instruction sequence in the privileged code as well as the fact that memory read from address to which a recent memory write has occurred may see an older value and subsequently cause an update 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 read privileged memory by conducting targeted cache side-channel attacks.(CVE-2018-3639)

By mmap()ing a FUSE-backed file onto a process’s memory containing command line arguments (or environment strings), an attacker can cause utilities from psutils or procps (such as ps, w) or any other program which makes a read() call to the /proc/<pid>/cmdline (or /proc/<pid>/environ) files to block indefinitely (denial of service) or for some controlled time (as a synchronization primitive for other attacks).(CVE-2018-1120)

An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of instructions past bounds check. The flaw relies on the presence of a precisely-defined instruction sequence in the privileged code and the fact that memory writes occur to an address which depends on the untrusted value. Such writes cause an update 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 influence speculative execution and/or read privileged memory by conducting targeted cache side-channel attacks.(CVE-2018-3693)

Affected Packages:

kernel

Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.

Issue Correction:
Run yum update kernel and reboot the instance to update your system.

New Packages:

src:  
    kernel-4.14.47-63.37.amzn2.src  
  
x86_64:  
    kernel-4.14.47-63.37.amzn2.x86_64  
    kernel-headers-4.14.47-63.37.amzn2.x86_64  
    kernel-debuginfo-common-x86_64-4.14.47-63.37.amzn2.x86_64  
    perf-4.14.47-63.37.amzn2.x86_64  
    perf-debuginfo-4.14.47-63.37.amzn2.x86_64  
    python-perf-4.14.47-63.37.amzn2.x86_64  
    python-perf-debuginfo-4.14.47-63.37.amzn2.x86_64  
    kernel-tools-4.14.47-63.37.amzn2.x86_64  
    kernel-tools-devel-4.14.47-63.37.amzn2.x86_64  
    kernel-tools-debuginfo-4.14.47-63.37.amzn2.x86_64  
    kernel-devel-4.14.47-63.37.amzn2.x86_64  
    kernel-debuginfo-4.14.47-63.37.amzn2.x86_64  

Additional References

Red Hat: CVE-2018-1120, CVE-2018-3639, CVE-2018-3693

Mitre: CVE-2018-1120, CVE-2018-3639, CVE-2018-3693

4.7 Medium

CVSS2

Attack Vector

LOCAL

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

NONE

Availability Impact

NONE

AV:L/AC:M/Au:N/C:C/I:N/A:N

5.6 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

6.9 Medium

AI Score

Confidence

High

0.003 Low

EPSS

Percentile

65.2%