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CVE Record

CVE-2024-1635: Undertow: out-of-memory error after several closed connections with wildfly-http-client protocol

A vulnerability was found in Undertow. This vulnerability impacts a server that supports the wildfly-http-client protocol. Whenever a malicious user opens and closes a connection with the HTTP port of the server and then closes the connection immediately, the server will end with both memory and open file limits exhausted at some point, depending on the amount of memory available. At HTTP upgrade to remoting, the WriteTimeoutStreamSinkConduit leaks connections if RemotingConnection is closed by Remoting ServerConnectionOpenListener. Because the remoting connection originates in Undertow as part of the HTTP upgrade, there is an external layer to the remoting connection. This connection is unaware of the outermost layer when closing the connection during the connection opening procedure. Hence, the Undertow WriteTimeoutStreamSinkConduit is not notified of the closed connection in this scenario. Because WriteTimeoutStreamSinkConduit creates a timeout task, the whole dependency tree leaks via that task, which is added to XNIO WorkerThread. So, the workerThread points to the Undertow conduit, which contains the connections and causes the leak.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2024-1635 is a denial-of-service issue in Undertow when servers support the wildfly-http-client protocol. An unauthenticated network user can cause memory and open file handles to be exhausted, potentially taking application services offline. The issue is availability-focused; the provided sources do not indicate data theft or tampering.

Executive priority

Treat as a high-priority availability risk for business-critical Java application servers. Prioritize externally reachable or high-traffic JBoss EAP/Undertow services. If affected systems are internal and monitored, schedule rapid patching through normal change control; if exposed, accelerate remediation and add monitoring.

Technical view

During HTTP upgrade to remoting, Undertow’s WriteTimeoutStreamSinkConduit can retain timeout tasks after a remoting connection is closed during opening. XNIO worker threads then keep references to the conduit and connection tree, causing memory and file descriptor leaks. CVSS is 7.5, network exploitable, low complexity, no privileges, availability impact only.

Likely exposure

Exposure is most likely on internet- or network-reachable Undertow/JBoss EAP services with the wildfly-http-client protocol enabled. The source bundle lists affected Red Hat JBoss Enterprise Application Platform packages and related Red Hat advisories. Non-Red Hat Undertow deployments need vendor or dependency validation because fixed version details are incomplete here.

Exploitation context

The CVE is not listed as CISA KEV in the provided data, and no cited source states active exploitation. Abuse requires reaching the server HTTP port and triggering the vulnerable connection lifecycle repeatedly. The business impact is service degradation or outage from resource exhaustion.

Researcher notes

This is CWE-400 resource consumption caused by a lifecycle cleanup gap around Undertow remoting upgrade handling. The source bundle provides strong Red Hat product/advisory signals but limited upstream fixed-version detail. Do not assume active exploitation without additional evidence; focus validation on reachable protocol support and package advisory status.

Mitigation direction

  • Apply the relevant Red Hat security advisories for affected JBoss EAP packages.
  • Check vendor guidance for non-Red Hat Undertow or bundled Undertow deployments.
  • Limit network exposure of affected HTTP endpoints where business requirements allow.
  • Monitor memory and file descriptor usage until updates are deployed.
  • Review whether wildfly-http-client protocol support is required on exposed services.

Validation and detection

  • Inventory applications using Undertow, WildFly, or Red Hat JBoss EAP.
  • Map installed package versions to Red Hat CVE and errata applicability.
  • Confirm whether the wildfly-http-client protocol is enabled or reachable.
  • Check logs and metrics for unexplained memory or file descriptor growth.
  • Verify patched advisory levels after maintenance is completed.
Prepared
Confidence
medium
Sources
7

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

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cwe · low confidence lookup

CWE-400: Exact CWE lookup

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cve · low confidence lookup

CVE-2024-1635 mapping review

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

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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
17Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical 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-2024-1635Attack 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

    Made public.

  2. Source timelineredhat

    Reported to Red Hat.

  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, 1.31.0unaffected
Red HatRed Hat build of Apache Camel 4.4.1 for Spring Boot 3.2See advisoryunaffected
Red HatRed Hat Fuse 7.13.0See advisoryunaffected
Red HatRed Hat JBoss Enterprise Application Platformio.undertow/undertow-core, 2.2.30.SP1-redhat-00001affected
Red HatRed Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7eap7-activemq-artemis, 0:1.5.5.016-1.redhat_00001.1.ep7.el7affected
Red HatRed Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7eap7-artemis-native, 1:1.5.5.016-1.redhat_00001.1.ep7.el7affected
Red HatRed Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7eap7-jboss-xnio-base, 0:3.5.11-1.Final_redhat_00001.1.ep7.el7affected
Red HatRed Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7eap7-jsoup, 0:1.14.2-1.redhat_00002.1.ep7.el7affected
Red HatRed Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7eap7-undertow, 0:1.4.18-14.SP13_redhat_00001.1.ep7.el7affected
Red HatRed Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7eap7-wildfly, 0:7.1.10-2.GA_redhat_00002.1.ep7.el7affected
Red HatRed Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7eap7-woodstox-core, 0:5.0.3-2.redhat_00002.1.ep7.el7affected
Red HatRed Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7eap7-xml-security, 0:2.0.10-2.redhat_00002.1.ep7.el7affected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-jackson-annotations, 0:2.10.4-3.redhat_00006.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-jackson-core, 0:2.10.4-3.redhat_00006.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-jackson-databind, 0:2.10.4-5.redhat_00006.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-jackson-jaxrs-providers, 0:2.10.4-3.redhat_00006.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-jackson-modules-base, 0:2.10.4-5.redhat_00006.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-jackson-modules-java8, 0:2.10.4-2.redhat_00006.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-jboss-server-migration, 0:1.7.2-16.Final_redhat_00017.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-netty, 0:4.1.63-5.Final_redhat_00003.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-undertow, 0:2.0.41-4.SP5_redhat_00001.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-wildfly, 0:7.3.14-3.GA_redhat_00002.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7eap7-wildfly-elytron, 0:1.10.17-1.Final_redhat_00001.1.el7eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.4 for RHEL 8eap7-undertow, 0:2.2.30-1.SP1_redhat_00001.1.el8eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.4 for RHEL 9eap7-undertow, 0:2.2.30-1.SP1_redhat_00001.1.el9eapaffected
Red HatRed Hat JBoss Enterprise Application Platform 7.4 on RHEL 7eap7-undertow, 0:2.2.30-1.SP1_redhat_00001.1.el7eapaffected
Red HatRed Hat Single Sign-On 7.6 for RHEL 7rh-sso7-keycloak, 0:18.0.13-1.redhat_00001.1.el7ssoaffected
Red HatRed Hat Single Sign-On 7.6 for RHEL 8rh-sso7-keycloak, 0:18.0.13-1.redhat_00001.1.el8ssoaffected
Red HatRed Hat Single Sign-On 7.6 for RHEL 9rh-sso7-keycloak, 0:18.0.13-1.redhat_00001.1.el9ssoaffected
Red HatRHEL-8 based Middleware Containersrh-sso-7/sso76-openshift-rhel8, 7.6-46affected
Weakness

CWE details

CWE-400

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

CWE-400 · source CWE mapping

CWE mapping pending import

This CVE carries a CWE mapping that will resolve to a full Glexia CWE intelligence page after the official CWE import is complete.

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