CVE-2019-20437

Name: CVE-2019-20437
Creator: NVD / NIST
Published: 2020-01-28T01:15:12.037+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 1.28%

Last modified Jun 17, 2026

CVE-2019-20437 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. 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. EPSS estimates a 1.28% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

1.28%

66.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Wso2	Api Manager	2.6.0
Wso2	Identity Server	5.7.0
Wso2	Identity Server	5.8.0

References

https://cybersecurityworks.com/zerodays/cve-2019-20437-wso2.htmlExploit, Third Party Advisory
https://docs.wso2.com/display/Security/Security+Advisory+WSO2-2019-0635Vendor Advisory
https://github.com/cybersecurityworks/Disclosed/issues/20Exploit, Third Party Advisory
https://cybersecurityworks.com/zerodays/cve-2019-20437-wso2.htmlExploit, Third Party Advisory
https://docs.wso2.com/display/Security/Security+Advisory+WSO2-2019-0635Vendor Advisory
https://github.com/cybersecurityworks/Disclosed/issues/20Exploit, Third Party Advisory

Timeline

Published: Jan 28, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-20437?

How severe is CVE-2019-20437?

CVE-2019-20437 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 1.28% probability of exploitation in the next 30 days.

How do I fix CVE-2019-20437?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-20437?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST