THREATPORT/VULNERABILITY/CVE-2021-42340
HIGH SEVERITY

CVE-2021-42340

Tomcat vulnerability

CVSS
7.5
EPSS
11.0%
EPSS pct
95th
Exploited
No known
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.
Affected vendor
Apache
Affected product
Tomcat
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness type (CWE)
  • CWE-772 — Missing Release of Resource after Effective Lifetime
Published
2021-10-14

Risk analysis

Based on its CVSS vector, this vulnerability is exploitable over the network, low attack complexity, requiring no privileges, no user interaction. Successful exploitation leads to high impact to availability.

Its EPSS score of 11.0% reflects a moderate probability of exploitation activity in the wild over the next 30 days, placing it above 95% of all scored CVEs.

Check your external exposure to CVE-2021-42340

  • Confirm whether Apache Tomcat is running on any internet-facing host or subdomain.
  • Match discovered service fingerprints against the version affected by CVE-2021-42340.
  • Prioritise remediation if the asset is public, business-critical, or near authentication/payment flows.

How ThreatPort helps with CVE-2021-42340

ThreatPort's external attack surface scanner checks your internet-facing assets — agentlessly, from the outside in — for the exposed services and versions that CVE-2021-42340 affects, then prioritises the finding by real risk using CISA KEV and FIRST.org EPSS.

Run a free external exposure scan

Are you exposed to CVE-2021-42340?

Run an instant, non-intrusive external scan to check your attack surface for CVE-2021-42340.

Start free scan

No credit card. Agentless.

Related vulnerabilities

HIGH
CVE-2015-7372
Revive Adserver vulnerability
HIGH
CVE-2015-5569
Flash Player vulnerability
HIGH
CVE-2015-5586
Acrobat vulnerability