Amazon Linux 2 : openssl11 (ALAS-2023-2039)

medium Nessus Plugin ID 175969

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 ALAS2-2023-2039 advisory.

A security vulnerability has been identified in all supported versions of OpenSSL related to the verification of X.509 certificate chains that include policy constraints. Attackers may be able to exploit this vulnerability by creating a malicious certificate chain that triggers exponential use of computational resources, leading to a denial-of-service (DoS) attack on affected systems. Policy processing is disabled by default but can be enabled by passing the `-policy' argument to the command line utilities or by calling the `X509_VERIFY_PARAM_set1_policies()' function. (CVE-2023-0464)

Applications that use a non-default option when verifying certificates may be vulnerable to an attack from a malicious CA to circumvent certain checks. Invalid certificate policies in leaf certificates are silently ignored by OpenSSL and other certificate policy checks are skipped for that certificate. A malicious CA could use this to deliberately assert invalid certificate policies in order to circumvent policy checking on the certificate altogether. Policy processing is disabled by default but can be enabled by passing the `-policy' argument to the command line utilities or by calling the `X509_VERIFY_PARAM_set1_policies()' function. (CVE-2023-0465)

The function X509_VERIFY_PARAM_add0_policy() is documented to implicitly enable the certificate policy check when doing certificate verification. However the implementation of the function does not enable the check which allows certificates with invalid or incorrect policies to pass the certificate verification.
As suddenly enabling the policy check could break existing deployments it was decided to keep the existing behavior of the X509_VERIFY_PARAM_add0_policy() function. Instead the applications that require OpenSSL to perform certificate policy check need to use X509_VERIFY_PARAM_set1_policies() or explicitly enable the policy check by calling X509_VERIFY_PARAM_set_flags() with the X509_V_FLAG_POLICY_CHECK flag argument.
Certificate policy checks are disabled by default in OpenSSL and are not commonly used by applications.
(CVE-2023-0466)

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 openssl11' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALAS-2023-2039.html

https://alas.aws.amazon.com/cve/html/CVE-2023-0464.html

https://alas.aws.amazon.com/cve/html/CVE-2023-0465.html

https://alas.aws.amazon.com/cve/html/CVE-2023-0466.html

https://alas.aws.amazon.com/faqs.html

Plugin Details

Severity: Medium

ID: 175969

File Name: al2_ALAS-2023-2039.nasl

Version: 1.2

Type: local

Agent: unix

Published: 5/17/2023

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: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

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

CVSS Score Source: CVE-2023-0466

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.6

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

Temporal Vector: CVSS:3.0/E:U/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 Ease: No known exploits are available

Patch Publication Date: 5/11/2023

Vulnerability Publication Date: 3/22/2023

Reference Information

CVE: CVE-2023-0464, CVE-2023-0465, CVE-2023-0466

IAVA: 2023-A-0158-S