Amazon Linux AMI update for kernel

Published: 2018-06-08 | Updated: 2018-06-12

Risk	High
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2018-1120 CVE-2018-3639
CWE-ID	CWE-20 CWE-362
Exploitation vector	Local
Public exploit	Public exploit code for vulnerability #1 is available.
Vulnerable software	Amazon Linux AMI Operating systems & Components / Operating system
Vendor	Amazon Web Services

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Improper input validation

EUVDB-ID: #VU12853

Risk: Low

CVSSv4.0: 5.4 [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]

CVE-ID: CVE-2018-1120

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

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).

Mitigation

Update the affected packages.

i686:
    kernel-tools-debuginfo-4.14.47-56.37.amzn1.i686
    perf-debuginfo-4.14.47-56.37.amzn1.i686
    kernel-devel-4.14.47-56.37.amzn1.i686
    kernel-debuginfo-common-i686-4.14.47-56.37.amzn1.i686
    kernel-tools-devel-4.14.47-56.37.amzn1.i686
    kernel-debuginfo-4.14.47-56.37.amzn1.i686
    perf-4.14.47-56.37.amzn1.i686
    kernel-headers-4.14.47-56.37.amzn1.i686
    kernel-4.14.47-56.37.amzn1.i686
    kernel-tools-4.14.47-56.37.amzn1.i686

src:
    kernel-4.14.47-56.37.amzn1.src

x86_64:
    perf-debuginfo-4.14.47-56.37.amzn1.x86_64
    kernel-headers-4.14.47-56.37.amzn1.x86_64
    kernel-debuginfo-4.14.47-56.37.amzn1.x86_64
    kernel-4.14.47-56.37.amzn1.x86_64
    kernel-tools-debuginfo-4.14.47-56.37.amzn1.x86_64
    perf-4.14.47-56.37.amzn1.x86_64
    kernel-devel-4.14.47-56.37.amzn1.x86_64
    kernel-tools-devel-4.14.47-56.37.amzn1.x86_64
    kernel-tools-4.14.47-56.37.amzn1.x86_64
    kernel-debuginfo-common-x86_64-4.14.47-56.37.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

CPE2.3

cpe:2.3:o:amazon_web_services:amazon_linux_ami:*:*:*:*:*:*:*:*

External links

https://alas.aws.amazon.com/ALAS-2018-1038.html

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

2) Speculative Store Bypass

EUVDB-ID: #VU12911

Risk: Low

CVSSv4.0: 4.3 [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]

CVE-ID: CVE-2018-3639

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No