How severe is CVE-2019-20437?

CVE-2019-20437 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2019-20437 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-20437?

CVE-2019-20437 primarily affects Wso2 Api Manager. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-20437?

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

When was CVE-2019-20437 published?

CVE-2019-20437 was published on 2020-01-28 and last updated on 2026-06-17.

CVE-2019-20437

CVE-2019-20437 is a medium-severity vulnerability in Wso2 Api Manager with a CVSS 3.x base score of 6.1. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (66th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Wso2 Api Manager
Published: 2020-01-28
Last modified: 2026-06-17

Description

An issue was discovered in WSO2 API Manager 2.6.0, WSO2 IS as Key Manager 5.7.0, and WSO2 Identity Server 5.8.0. When a custom claim dialect with an XSS payload is configured in the identity provider basic claim configuration, that payload gets executed, if a user picks up that dialect's URI as the provisioning claim in the advanced claim configuration of the same Identity Provider. The attacker also needs to have privileges to log in to the management console, and to add and update identity provider configurations.

Frequently asked questions

What is CVE-2019-20437?: An issue was discovered in WSO2 API Manager 2.6.0, WSO2 IS as Key Manager 5.7.0, and WSO2 Identity Server 5.8.0. When a custom claim dialect with an XSS payload is configured in the identity provider basic claim configuration, that payload gets executed, if a user picks up that dialect's URI as the provisioning claim in the advanced claim configuration of the same Identity Provider. The attacker also needs to have privileges to log in to the management console, and to add and update identity provider configurations.
How severe is CVE-2019-20437?: CVE-2019-20437 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2019-20437 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-20437?: CVE-2019-20437 primarily affects Wso2 Api Manager. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-20437?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2019-20437 published?: CVE-2019-20437 was published on 2020-01-28 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:wso2:api_manager:2.6.0:*:*:*:*:*:*:*
cpe:2.3:a:wso2:identity_server:5.7.0:*:*:*:*:*:*:*
cpe:2.3:a:wso2:identity_server:5.8.0:*:*:*:*:*:*:*

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