CVE-2024-1635
Published: 19 February 2024
Summary
CVE-2024-1635 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Netapp Active Iq Unified Manager. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked in the top 4.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
CVE-2024-1635 is a resource-exhaustion vulnerability in Undertow that affects servers implementing the wildfly-http-client protocol. When an HTTP connection is upgraded to remoting, the WriteTimeoutStreamSinkConduit fails to release the connection if the Remoting ServerConnectionOpenListener closes the RemotingConnection during the opening sequence. The resulting timeout task remains referenced by an XNIO WorkerThread, causing the entire conduit and connection object graph to leak and eventually exhaust memory and open-file limits.
An unauthenticated remote attacker can trigger the flaw simply by repeatedly opening and immediately closing connections to the server’s HTTP port. Because the vector requires no credentials or user interaction and yields a high availability impact, an attacker can render the affected service unavailable after a modest number of requests.
Red Hat has published the following advisories that contain patched builds and mitigation guidance: RHSA-2024:1674, RHSA-2024:1675, RHSA-2024:1676, RHSA-2024:1677, and RHSA-2024:1860. The current EPSS score of 0.23 (peak 0.23) reflects moderate but stable exploitation interest since disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-0747
Vulnerability details
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability allows remote attackers to exhaust memory and open file limits via repeated connection open/close during HTTP upgrade to wildfly-http-client protocol, facilitating endpoint denial of service through application exploitation.
MITRE ATLAS TechniquesAI
MITRE ATLAS techniques
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Limiting concurrent sessions directly prevents uncontrolled resource consumption by capping the number of active sessions per user or account.
Analysis identifies uncontrolled resource consumption indicative of denial-of-service or abuse attempts.
Contingency plan testing includes resource exhaustion scenarios to verify recovery, making it harder for attackers to sustain exploits that cause uncontrolled consumption.
Updated contingency plans include current procedures to detect, contain, and recover from resource exhaustion, limiting an attacker's ability to sustain impact from uncontrolled consumption.
Alternate site allows resumption of operations if resource exhaustion at the primary site is exploited to cause unavailability.
Alternate telecommunications services enable resumption of essential functions when primary services become unavailable due to uncontrolled resource consumption.
The team can analyze and respond to resource exhaustion incidents, reducing the impact of attacks that exploit uncontrolled consumption weaknesses.
Timely maintenance support and spare parts enable rapid recovery from failures induced by uncontrolled resource consumption, shortening the impact window of denial-of-service attacks.