Amazon Linux 2 : curl (ALAS-2021-1724)

high Nessus Plugin ID 155980

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of curl installed on the remote host is prior to 7.79.1-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1724 advisory.

A flaw was found in libcurl. When sending data to an MQTT server could in some situations lead to libcurl using already freed memory and then try to free it again. The highest threat from this vulnerability is to data confidentiality as well as system availability. (CVE-2021-22945)

A flaw was found in curl. This flaw lies in the --ssl-reqd option or related settings in libcurl. Users specify this flag to upgrade to TLS when communicating with either IMAP, POP3 or a FTP server. An attacker controlling such servers could return a crafted response which could lead to curl client continue its operation without TLS encryption leading to data being transmitted in clear text over the network. The highest threat from this vulnerability is to data confidentiality. (CVE-2021-22946)

A flaw was found in curl. The flaw lies in how curl handles cached or pipelined responses that it receives from either a IMAP, POP3, SMTP or FTP server before the TLS upgrade using STARTTLS. In such a scenario curl even after upgrading to TLS would trust these cached responses treating them as valid and authenticated and use them. An attacker could potentially use this flaw to carry out a Man-In-The-Middle attack. The highest threat from this vulnerability is to data confidentiality. (CVE-2021-22947)

Tenable has extracted the preceding description block directly from the tested product security advisory.

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

Solution

Run 'yum update curl' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALAS-2021-1724.html

https://access.redhat.com/security/cve/CVE-2021-22945

https://alas.aws.amazon.com/cve/html/CVE-2021-22946.html

https://alas.aws.amazon.com/cve/html/CVE-2021-22947.html

Plugin Details

Severity: High

ID: 155980

File Name: al2_ALAS-2021-1724.nasl

Version: 1.4

Type: local

Agent: unix

Published: 12/10/2021

Updated: 12/11/2024

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.0

CVSS v2

Risk Factor: Medium

Base Score: 5.8

Temporal Score: 4.5

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

CVSS Score Source: CVE-2021-22945

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 8.2

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

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

CVSS v4

Risk Factor: High

Base Score: 8.9

Threat Score: 8.9

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS Score Source: CVE-2021-22947

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:libcurl, p-cpe:/a:amazon:linux:libcurl-devel, p-cpe:/a:amazon:linux:curl-debuginfo, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:curl

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: 12/8/2021

Vulnerability Publication Date: 9/17/2021

Reference Information

CVE: CVE-2021-22945, CVE-2021-22946, CVE-2021-22947

ALAS: 2021-1724