How severe is CVE-2021-37151?

CVE-2021-37151 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-37151 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-37151?

CVE-2021-37151 affects Cyberark Identity. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-37151?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-37151 published?

CVE-2021-37151 was published on 2021-09-01 and last updated on 2026-06-17.

CVE-2021-37151

CVE-2021-37151 is a medium-severity vulnerability in Cyberark Identity with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-203.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 1% (54th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-203
Affected product: Cyberark Identity
Published: 2021-09-01
Last modified: 2026-06-17

Description

CyberArk Identity 21.5.131, when handling an invalid authentication attempt, sometimes reveals whether the username is valid. In certain authentication policy configurations with MFA, the API response length can be used to differentiate between a valid user and an invalid one (aka Username Enumeration). Response differentiation enables attackers to enumerate usernames of valid application users. Attackers can use this information to leverage brute-force and dictionary attacks in order to discover valid account information such as passwords.

Frequently asked questions

What is CVE-2021-37151?: CyberArk Identity 21.5.131, when handling an invalid authentication attempt, sometimes reveals whether the username is valid. In certain authentication policy configurations with MFA, the API response length can be used to differentiate between a valid user and an invalid one (aka Username Enumeration). Response differentiation enables attackers to enumerate usernames of valid application users. Attackers can use this information to leverage brute-force and dictionary attacks in order to discover valid account information such as passwords.
How severe is CVE-2021-37151?: CVE-2021-37151 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-37151 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-37151?: CVE-2021-37151 affects Cyberark Identity. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-37151?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-37151 published?: CVE-2021-37151 was published on 2021-09-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:cyberark:identity:*:*:*:*:*:*:*:*

More vulnerabilities in Cyberark Identity

CVE-2024-42340 — High (CVSS 8.3): CyberArk - CWE-602: Client-Side Enforcement of Server-Side Security
CVE-2022-22700 — Medium (CVSS 5.3): CyberArk Identity versions up to and including 22.1 in the 'StartAuthentication' resource, exposes the response header…
CVE-2024-42339 — Medium (CVSS 4.3): CyberArk - CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
CVE-2024-42338 — Medium (CVSS 4.3): CyberArk - CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
CVE-2024-42337 — Medium (CVSS 4.3): CyberArk - CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

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