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5.9Medium

Apache Tomcat

CVE-2021-24122

When serving resources from a network location using the NTFS file system, Apache Tomcat versions 10.0.0-M1 to 10.0.0-M9, 9.0.0.M1 to 9.0.39, 8.5.0 to 8.5.59 and 7.0.0 to 7.0.106 were susceptible to JSP source code disclosure in some configurations. The root cause was the unexpected behaviour of the JRE API File.getCanonicalPath() which in turn was caused by the inconsistent behaviour of the Windows API (FindFirstFileW) in some circumstances.

What this means for your business

  • It affects Apache Tomcat. It matters if your company, or a supplier that handles your data, runs it.
  • An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.

What to do

  1. 1Check whether your company or your suppliers run Apache Tomcat, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Check if you’re exposedBook a call

Scoring

CVSS
5.9 (v3.1)
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness
CWE-200
Assigned by
security@apache.org

Dates

Published
2021-01-14
Last modified
2026-08-25
Sources
NVD

Affected products

  • Apache Tomcat7.0.0 - 7.0.106, 8.5.0 - 8.5.59, 9.0.1 - 9.0.39, 9.0.0, 10.0.0
  • Debian Debian Linux9.0
  • Oracle Agile Product Lifecycle Management9.3.3, 9.3.6

As listed in the NVD configuration data. Not a statement about your estate.

References