Skip to content
TrackCVE
  • Newest CVEsPage
  • Recently added to KEVPage
  • Rising exploitation (EPSS)Page
  • Weekly digestPage
  • StatisticsPage
  • WatchlistPage
  • API documentationPage
  • MCP serverPage
  • Data sourcesPage
  • ChangelogPage
  • AboutPage
  • How it's builtPage
Back

CVE-2020-1938

When using the Apache JServ Protocol (AJP), care must be taken when trusting incoming connections to Apache Tomcat. Tomcat treats AJP…

Critical9.8Known exploitedPublic exploitEPSS 99.3%
Published
Updated
Reserved
Assigned by
apache

Description

When using the Apache JServ Protocol (AJP), care must be taken when trusting incoming connections to Apache Tomcat. Tomcat treats AJP connections as having higher trust than, for example, a similar HTTP connection. If such connections are available to an attacker, they can be exploited in ways that may be surprising. In Apache Tomcat 9.0.0.M1 to 9.0.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99, Tomcat shipped with an AJP Connector enabled by default that listened on all configured IP addresses. It was expected (and recommended in the security guide) that this Connector would be disabled if not required. This vulnerability report identified a mechanism that allowed: - returning arbitrary files from anywhere in the web application - processing any file in the web application as a JSP Further, if the web application allowed file upload and stored those files within the web application (or the attacker was able to control the content of the web application by some other means) then this, along with the ability to process a file as a JSP, made remote code execution possible. It is important to note that mitigation is only required if an AJP port is accessible to untrusted users. Users wishing to take a defence-in-depth approach and block the vector that permits returning arbitrary files and execution as JSP may upgrade to Apache Tomcat 9.0.31, 8.5.51 or 7.0.100 or later. A number of changes were made to the default AJP Connector configuration in 9.0.31 to harden the default configuration. It is likely that users upgrading to 9.0.31, 8.5.51 or 7.0.100 or later will need to make small changes to their configurations.

Exploited in the wild

CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Apache Tomcat Improper Privilege Management Vulnerability.

Added
3 Mar 2022
Fix due (US federal)
17 Mar 2022
Used by ransomware
Not known

Apply updates per vendor instructions.

Public exploit

An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: it is being exploited.

Timeline

  1. ID reserved

    By apache

  2. · 3 months later

    Published

  3. · 2 years later

    Added to CISA KEV

    Known exploited in the wild

  4. · 4 years later

    Record updated

Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.

Scores

CVSS scores of CVE-2020-1938, by who scored it
Scored byCVSSScoreVector
CISA-ADPADP (enrichment)3.1Critical9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVDNVD · Analyzed3.1Critical9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (exploitation in 30 days)
99.3% · top 0.1% of all CVEs (7 Nov 2026)
CISA SSVC
Exploitation: active · Automatable: yes · Technical impact: total
Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.

Weakness

  • AJP Request Injection leading to possible Remote Code Execution
  • CWE-noinfo Not enough information

Affected products

  • Apache · Apache Tomcat

    • affected Apache Tomcat 9.0.0.M1 to 9.0.0.30
    • affected 8.5.0 to 8.5.50
    • affected 7.0.0 to 7.0.99

Affected packages

From reviewed advisories of the GitHub Advisory Database.

References (52)

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

CVE-2020-1938 badge
[![CVE-2020-1938](https://trackcve.app/badge/CVE-2020-1938.svg)](https://trackcve.app/cve/CVE-2020-1938)

Record last updated .