Amazon Linux 2 : openssl11 (ALAS-2021-1622)

high Nessus Plugin ID 148196

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Synopsis

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

Description

The version of openssl11 installed on the remote host is prior to 1.1.1g-12. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1622 advisory.

- An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a signature_algorithms_cert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack. A server is only vulnerable if it has TLSv1.2 and renegotiation enabled (which is the default configuration). OpenSSL TLS clients are not impacted by this issue. All OpenSSL 1.1.1 versions are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1-1.1.1j). (CVE-2021-3449)

- The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain. It is not set by default. Starting from OpenSSL version 1.1.1h a check to disallow certificates in the chain that have explicitly encoded elliptic curve parameters was added as an additional strict check. An error in the implementation of this check meant that the result of a previous check to confirm that certificates in the chain are valid CA certificates was overwritten. This effectively bypasses the check that non-CA certificates must not be able to issue other certificates. If a purpose has been configured then there is a subsequent opportunity for checks that the certificate is a valid CA. All of the named purpose values implemented in libcrypto perform this check. Therefore, where a purpose is set the certificate chain will still be rejected even when the strict flag has been used. A purpose is set by default in libssl client and server certificate verification routines, but it can be overridden or removed by an application. In order to be affected, an application must explicitly set the X509_V_FLAG_X509_STRICT verification flag and either not set a purpose for the certificate verification or, in the case of TLS client or server applications, override the default purpose. OpenSSL versions 1.1.1h and newer are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k.
OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1h-1.1.1j).
(CVE-2021-3450)

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 openssl11' to update your system.

Plugin Details

Severity: High

ID: 148196

File Name: al2_ALAS-2021-1622.nasl

Version: 1.7

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 3/27/2021

Updated: 1/8/2024

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 5.8

Temporal Score: 4.5

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

CVSS Score Source: CVE-2021-3450

CVSS v3

Risk Factor: High

Base Score: 7.4

Temporal Score: 6.7

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:openssl11, p-cpe:/a:amazon:linux:openssl11-debuginfo, p-cpe:/a:amazon:linux:openssl11-devel, p-cpe:/a:amazon:linux:openssl11-static, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:openssl11-libs

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: 3/25/2021

Vulnerability Publication Date: 3/25/2021

Reference Information

CVE: CVE-2021-3449, CVE-2021-3450

ALAS: 2021-1622

IAVA: 2021-A-0149-S

Detections

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