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

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.

Published: 2023-10-26 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-31421 is rated Low Risk (32.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.11%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-31421

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-30 0.21% 0.11% -0.10%
2 2025-03-29 0.06% 0.21% +0.15%
3 2023-11-09 — 0.06% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-31421

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-31421

Affected software / configurations for CVE-2023-31421

Vendor Product Version Raw CPE
elastic elastic_beats >= 8.0.0, <= 8.9.2 cpe:2.3:a:elastic:elastic_beats:*:*:*:*:*:*:*:*
elastic elastic_agent >= 8.0.0, <= 8.9.2 cpe:2.3:a:elastic:elastic_agent:*:*:*:*:*:*:*:*
elastic apm_server >= 8.0.0, <= 8.9.2 cpe:2.3:a:elastic:apm_server:*:*:*:*:*:*:*:*
elastic elastic_fleet_server >= 8.0.0, <= 8.9.2 cpe:2.3:a:elastic:elastic_fleet_server:*:*:*:*:*:*:*:*

References for CVE-2023-31421

cvelogic Threat Intelligence