CVE-2021-37937 | Elasticsearch privilege escalation

An issue was found with how API keys are created with the Fleet-Server service account. When an API key is created with a service account, it is possible that the API key could be created with higher privileges than intended. Using this vulnerability, a compromised Fleet-Server service account could escalate themselves to a super-user.

Published: 2023-11-21 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-37937 is rated Moderate Risk (41.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.71%). Review affected assets and schedule remediation.

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-2021-37937

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 2026-06-15 0.27% 0.71% +0.45%
2 2026-06-02 0.24% 0.27% +0.02%
3 2025-11-21 — 0.24% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-37937

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:H/UI:N/S:U/C:H/I:H/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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 0.7 5.2 [email protected]
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H 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:L)
A normal user session is enough; they don’t have to be admin.
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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]

Weakness enumeration for CVE-2021-37937

OS Trackers for CVE-2021-37937

vendor priority summary link
ubuntu medium CVE-2021-37937 medium priority: Ubuntu including 1 source packages (elasticsearch), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 8, ignored 2, needs-triage 2. https://ubuntu.com/security/CVE-2021-37937

Affected software / configurations for CVE-2021-37937

Vendor Product Version Raw CPE
elastic elasticsearch >= 7.13.0, <= 7.14.0 cpe:2.3:a:elastic:elasticsearch:*:*:*:*:*:*:*:*

References for CVE-2021-37937

cvelogic Threat Intelligence