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CVE-2021-42340

DoS via memory leak with WebSocket connections

Exploitation likely. EPSS gives it a 12% chance of exploitation in the next 30 days. A vendor fix is available.

CVSS 3.17.5HighEPSS percentile96th12% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
No public exploit knownFixVendor fixNo build named by the sources

Published Updated Sources: CVE.org, NVD, GitHub, BDU

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

Check it yourselfA free Nuclei and OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Discuss checks for your systems with a specialist. Scope is agreed before testing.

What it is

From the CVE record

The fix for bug 63362 present in Apache Tomcat 10.1.0-M1 to 10.1.0-M5, 10.0.0-M1 to 10.0.11, 9.0.40 to 9.0.53 and 8.5.60 to 8.5.71 introduced a memory leak. The object introduced to collect metrics for HTTP upgrade connections was not released for WebSocket connections once the connection was closed. This created a memory leak that, over time, could lead to a denial of service via an OutOfMemoryError.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS96th
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

12% chance of exploitation activity in the next 30 days, which ranks it in the 96th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

7 events over 1715 days, from the signal feeds we watch.

  1. OpenVAS check added
  2. EPSS band changelow → moderate
  3. Nuclei check added
  4. Patch availablerecord updated
  5. Publishedweakness classified

Affected products

And 28 more affected products. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

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

Scored 7.5 by NVD.

How it is reached

  • Attack Vector NetworkExploitable remotely over the network without any special conditions
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality NoneNo confidentiality impact
  • Integrity NoneNo integrity impact
  • Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

Sources

References in the record

And 31 more references. See all after sign-in

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