CVE-2023-31421: Beats, Elastic Agent, APM Server, and Fleet Server Improper Certificate Validation issue

Description

It was discovered that when acting as TLS clients, Beats, Elastic Agent, APM Server, and Fleet Server did not verify whether the server certificate is valid for the target IP address; however, certificate signature validation is still performed. More specifically, when the client is configured to connect to an IP address (instead of a hostname) it does not validate the server certificate's IP SAN values against that IP address and certificate validation fails, and therefore the connection is not blocked as expected.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack vector

Network

Complexity

Low

Privileges

None

User interaction

None

Confidentiality

High

Integrity

None

Availability

None

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)0.3% · higher than 25% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

AS

APM Server · Elastic

8.0.0, 8.9.2 · source: vendor, NVD

BE

Beats · Elastic

8.0.0, 8.9.2 · source: vendor

EA

Elastic Agent · Elastic

8.0.0, 8.9.2 · source: vendor, NVD

FS

Fleet Server · Elastic

8.0.0, 8.9.2 · source: vendor

EB

Elastic Beats · Elastic

8.0.0 through 8.9.2 · source: NVD

EF

Elastic Fleet Server · Elastic

8.0.0 through 8.9.2 · source: NVD