title: Undertow: ajp request closes connection exceeding maxrequestsize
description: A flaw was found in Undertow. When an AJP request is sent that exceeds the max-header-size attribute in ajp-listener, JBoss EAP is marked in an error state by mod_cluster in httpd, causing JBoss EAP to close the TCP connection without returning an AJP response. This happens because mod_proxy_cluster marks the JBoss EAP instance as an error worker when the TCP connection is closed from the backend after sending the AJP request without receiving an AJP response, and stops forwarding. This issue could allow a malicious user could to repeatedly send requests that exceed the max-header-size, causing a Denial of Service (DoS).
problem types: Allocation of Resources Without Limits or Throttling
affected:
{
product: upstream
vendor: n/a
defaultStatus: affected
}
{
vendor: Red Hat
product: Red Hat JBoss Enterprise Application Platform 7.1.0
collectionURL: https://access.redhat.com/downloads/content/package-browser/
defaultStatus: unaffected
cpe: cpe:/a:redhat:jboss_enterprise_application_platform:7.4
}
{
vendor: Red Hat
product: Red Hat build of Quarkus
collectionURL: https://access.redhat.com/downloads/content/package-browser/
packageName: io.quarkus/quarkus-undertow
defaultStatus: unaffected
cpes: cpe:/a:redhat:quarkus:2
}
{
vendor: Red Hat
product: Red Hat Data Grid 8
collectionURL: https://access.redhat.com/downloads/content/package-browser/
packageName: undertow
defaultStatus: unaffected
cpes: cpe:/a:redhat:jboss_data_grid:8
}
{
vendor: Red Hat
product: Red Hat Decision Manager 7
collectionURL: https://access.redhat.com/downloads/content/package-browser/
packageName: undertow
defaultStatus: unknown
cpes: cpe:/a:redhat:jboss_enterprise_brms_platform:7
}
{
vendor: Red Hat
product: Red Hat JBoss Data Grid 7
collectionURL: https://access.redhat.com/jbossnetwork/restricted/listSoftware.html
packageName: undertow
defaultStatus: unknown
cpes: cpe:/a:redhat:jboss_data_grid:7
}
{
vendor: Red Hat
product: Red Hat JBoss Enterprise Application Platform 7
collectionURL: https://access.redhat.com/jbossnetwork/restricted/listSoftware.html
packageName: undertow
defaultStatus: affected
cpes: cpe:/a:redhat:jboss_enterprise_application_platform:7
}
{
vendor: Red Hat
product: Red Hat JBoss Fuse 6
collectionURL: https://access.redhat.com/jbossnetwork/restricted/listSoftware.html
packageName: undertow
defaultStatus: unknown
cpes: cpe:/a:redhat:jboss_fuse:6
}
{
vendor: Red Hat
product: Red Hat JBoss Fuse 7
collectionURL: https://access.redhat.com/jbossnetwork/restricted/listSoftware.html
packageName: undertow
defaultStatus: unknown
cpes: cpe:/a:redhat:jboss_fuse:7
}
{
vendor: Red Hat
product: Red Hat Process Automation 7
collectionURL: https://access.redhat.com/downloads/content/package-browser/
packageName: undertow
defaultStatus: unknown
cpes: cpe:/a:redhat:jboss_enterprise_bpms_platform:7
}
{
vendor: Red Hat
product: Red Hat Single Sign-On 7
collectionURL: https://access.redhat.com/downloads/content/package-browser/
packageName: undertow
defaultStatus: affected
cpes: cpe:/a:redhat:red_hat_single_sign_on:7
}
{
vendor: Red Hat
product: Red Hat support for Spring Boot
collectionURL: https://access.redhat.com/downloads/content/package-browser/
packageName: undertow
defaultStatus: unaffected
cpes: cpe:/a:redhat:openshift_application_runtimes:1.0
}
metrics:
other: [
content: {'value': 'Moderate', 'namespace': 'https://access.redhat.com/security/updates/classification/'}
type: Red Hat severity rating
]