Amazon Linux AMI : exim (ALAS-2021-1497)

critical Nessus Plugin ID 149430

Synopsis

The remote Amazon Linux AMI host is missing a security update.

Description

The version of exim installed on the remote host is prior to 4.92-1.27. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS-2021-1497 advisory.

- Exim 4 before 4.94.2 has Improper Neutralization of Line Delimiters. Local users can alter the behavior of root processes because a recipient address can have a newline character. (CVE-2020-28015)

- Exim 4 before 4.94.2 allows Integer Overflow to Buffer Overflow in receive_add_recipient via an e-mail message with fifty million recipients. NOTE: remote exploitation may be difficult because of resource consumption. (CVE-2020-28017)

- Exim 4 before 4.94.2 allows Use After Free in smtp_reset in certain situations that may be common for builds with OpenSSL. (CVE-2020-28018)

- Exim 4 before 4.94.2 has Improper Neutralization of Line Delimiters. An authenticated remote SMTP client can insert newline characters into a spool file (which indirectly leads to remote code execution as root) via AUTH= in a MAIL FROM command. (CVE-2020-28021)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Run 'yum update exim' to update your system.

See Also

https://alas.aws.amazon.com/ALAS-2021-1497.html

https://access.redhat.com/security/cve/CVE-2020-28015

https://access.redhat.com/security/cve/CVE-2020-28017

https://access.redhat.com/security/cve/CVE-2020-28018

https://access.redhat.com/security/cve/CVE-2020-28021

Plugin Details

Severity: Critical

ID: 149430

File Name: ala_ALAS-2021-1497.nasl

Version: 1.4

Type: local

Agent: unix

Published: 5/12/2021

Updated: 1/2/2024

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 9

Temporal Score: 7

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

CVSS Score Source: CVE-2020-28021

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS Score Source: CVE-2020-28018

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:exim, p-cpe:/a:amazon:linux:exim-debuginfo, p-cpe:/a:amazon:linux:exim-pgsql, p-cpe:/a:amazon:linux:exim-mon, p-cpe:/a:amazon:linux:exim-greylist, cpe:/o:amazon:linux, p-cpe:/a:amazon:linux:exim-mysql

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/6/2021

Vulnerability Publication Date: 5/6/2021

Reference Information

CVE: CVE-2020-28015, CVE-2020-28017, CVE-2020-28018, CVE-2020-28021

ALAS: 2021-1497