CVE-2019-20104

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-02-06 · updated 2026-06-17
Weakness: CWE-776

Description

The OpenID client application in Atlassian Crowd before version 3.6.2, and from version 3.7.0 before 3.7.1 allows remote attackers to perform a Denial of Service attack via an XML Entity Expansion vulnerability.

Affected products

Atlassian Crowd: before 3.2.11; from 3.3.0 before 3.3.8; from 3.4.0 before 3.4.7; from 3.5.0 before 3.5.2; from 3.6.0 before 3.6.2; from 3.6.3 before 3.7.1 — fixed in 3.2.11, 3.3.8, 3.4.7, 3.5.2, 3.6.2, 3.7.1

How to fix

Upgrade to a fixed version: Atlassian Crowd 3.2.11, 3.3.8, 3.4.7, 3.5.2. Check the vendor advisory for mitigations.

References

https://jira.atlassian.com/browse/CWD-5526
https://zeroauth.ltd/blog/2020/02/07/cve-2019-20104-atlassian-crowd-openid-client-vulnerable-to-remote-dos-via-xml-entity-expansion/
https://jira.atlassian.com/browse/CWD-5526
https://zeroauth.ltd/blog/2020/02/07/cve-2019-20104-atlassian-crowd-openid-client-vulnerable-to-remote-dos-via-xml-entity-expansion/

Get alerted when CVE-2019-20104 or the next vulnerability affects your stack