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CVE Record

CVE-2025-9784: Undertow: undertow madeyoureset http/2 ddos vulnerability

A flaw was found in Undertow where malformed client requests can trigger server-side stream resets without triggering abuse counters. This issue, referred to as the "MadeYouReset" attack, allows malicious clients to induce excessive server workload by repeatedly causing server-side stream aborts. While not a protocol bug, this highlights a common implementation weakness that can be exploited to cause a denial of service (DoS).

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2025-9784 is a remotely triggerable denial-of-service weakness in Undertow’s HTTP/2 request handling. Malicious clients can repeatedly make the server reset streams without activating intended abuse counters, consuming resources and potentially disrupting applications. The issue affects availability, not confidentiality or data integrity.

Executive priority

Prioritize remediation for externally reachable business services because an unauthenticated attacker could degrade availability. Patch according to vendor guidance on an expedited schedule, while confirming exact product applicability to avoid acting on ambiguous package mappings. Internal-only or HTTP/2-disabled deployments can follow after exposure is verified.

Technical view

Malformed HTTP/2 client requests can cause Undertow to initiate stream resets that evade abuse accounting. Repetition can impose excessive server workload and exhaust resources. The issue is classified under CWE-404 and CWE-770 and scored CVSS 3.1 7.5: network-accessible, low-complexity, unauthenticated, and availability-impacting.

Likely exposure

Highest exposure exists where affected Undertow or Red Hat JBoss EAP services accept HTTP/2 traffic from untrusted networks. The bundle identifies multiple EAP 7.1, 7.3, 7.4, and 8.0 packages as affected, but also contains unaffected entries and incomplete version ranges; verify exact installed packages against Red Hat guidance.

Exploitation context

The supplied record is not in CISA KEV and provides no evidence of active exploitation. Exploitation is nevertheless plausible because the vulnerability is remotely reachable, requires no privileges or user interaction, and has low stated attack complexity. Treat internet-facing HTTP/2 services as the priority exposure group.

Researcher notes

The weakness is described as an implementation-level MadeYouReset condition, not an HTTP/2 protocol defect. Server-generated stream aborts bypass abuse counters, enabling asymmetric resource consumption. The source bundle’s affected-product data includes mixed affected and unaffected entries and some unexpected package mappings, so vendor advisory correlation is essential before declaring a host vulnerable.

Mitigation direction

  • Apply the Red Hat erratum matching the installed JBoss EAP product, operating system, and support channel.
  • Review Undertow’s upstream release and vendor guidance before selecting a fixed version.
  • Restrict untrusted HTTP/2 access where operationally feasible until applicable updates are installed.
  • Use rate limiting and resource protections as supplementary controls, not substitutes for vendor remediation.

Validation and detection

  • Inventory Undertow and JBoss EAP versions, package builds, operating systems, and support channels.
  • Confirm whether each service enables HTTP/2 and is reachable from untrusted networks.
  • Compare installed package builds with the applicable Red Hat CVE page and erratum.
  • After updating, verify package versions and monitor for abnormal stream resets or resource consumption.
  • Avoid destructive proof-of-concept testing on production systems.
Prepared
Confidence
medium
Sources
10

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-404: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cwe · low confidence lookup

CWE-770: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2025-9784 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
5Timeline events
2ADP providers
21Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2025-9784Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. Source timelineredhat

    Reported to Red Hat.

  2. Source timelineredhat

    Made public.

  3. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Unknown vendorundertowundertow, 0unaffected
Red HatRed Hat build of Apache Camel 4.14.2 for Spring Boot 3.5.8undertow-coreunaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7eap7-undertow, 0:1.4.18-21.SP19_redhat_00001.1.ep7.el7affected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-undertow, 0:2.0.41-8.SP9_redhat_00001.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.4.24io.undertow/undertow-core, 2.2.39.Final-redhat-00001affected
Red HatRed Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7eap7-undertow, 0:2.2.39-1.Final_redhat_00001.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7eap7-wildfly, 0:7.4.24-4.GA_redhat_00002.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8eap7-undertow, 0:2.2.39-1.Final_redhat_00001.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8eap7-wildfly, 0:7.4.24-4.GA_redhat_00002.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 9eap7-undertow, 0:2.2.39-1.Final_redhat_00001.1.el9eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 9eap7-wildfly, 0:7.4.24-4.GA_redhat_00002.1.el9eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0undertow-coreunaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 8eap8-bouncycastle, 0:1.83.0-1.redhat_00001.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 8eap8-guava-libraries, 0:33.0.0-2.jre_redhat_00003.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 8eap8-jaxb, 0:4.0.6-1.redhat_00001.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 8eap8-jcip-annotations, 0:1.0.0-3.redhat_00009.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 8eap8-slf4j-jboss-logmanager, 0:2.0.2-1.Final_redhat_00001.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 8eap8-undertow, 0:2.3.23-1.SP3_redhat_00001.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 9eap8-bouncycastle, 0:1.83.0-1.redhat_00001.1.el9eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 9eap8-guava-libraries, 0:33.0.0-2.jre_redhat_00003.1.el9eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 9eap8-jaxb, 0:4.0.6-1.redhat_00001.1.el9eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 9eap8-jcip-annotations, 0:1.0.0-3.redhat_00009.1.el9eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 9eap8-slf4j-jboss-logmanager, 0:2.0.2-1.Final_redhat_00001.1.el9eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.0 for RHEL 9eap8-undertow, 0:2.3.23-1.SP3_redhat_00001.1.el9eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.1undertow-coreunaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.1 for RHEL 8eap8-apache-cxf, 0:4.0.10-1.redhat_00001.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.1 for RHEL 8eap8-bouncycastle, 0:1.82.0-1.redhat_00001.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.1 for RHEL 8eap8-eap-product-conf-parent, 0:801.3.0-1.GA_redhat_00001.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.1 for RHEL 8eap8-eventstream, 0:1.0.1-3.redhat_00003.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 8.1 for RHEL 8eap8-hibernate, 0:6.6.36-1.Final_redhat_00001.1.el8eapaffected
Weakness

CWE details

CWE-404CWE-770

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.