# CVE-2020-1938: Apache Tomcat Improper Privilege Management Vulnerability

> CVE-2020-1938: Apache Tomcat Improper Privilege Management Vulnerability. CVSS 9.8 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2020-1938
Last updated: 2025-10-21T23:35:50Z

- Published: 2020-02-24 21:19 UTC · Updated: 2025-10-21 23:35 UTC · Assigner: apache
- CVSS: 9.8 (CVSS 3.1) · Severity: Critical · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS: 99.3%, 100th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2022-03-03, federal due date 2022-03-17, ransomware use: Unknown

## 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.

## CISA required action

Apply updates per vendor instructions.

## Affected vendors and products

- Apache: Apache Tomcat

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2020-1938)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2020-1938)
- [http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00025.html](http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00025.html)
- [http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00002.html](http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00002.html)
- [https://lists.apache.org/thread.html/r089dc67c0358a1556dd279c762c74f32d7a254a54836b7ee2d839d8e%40%3Cdev.tomee.apache.org%3E](https://lists.apache.org/thread.html/r089dc67c0358a1556dd279c762c74f32d7a254a54836b7ee2d839d8e%2540%3Cdev.tomee.apache.org%3E)
- [https://lists.apache.org/thread.html/r17aaa3a05b5b7fe9075613dd0c681efa60a4f8c8fbad152c61371b6e%40%3Cusers.tomcat.apache.org%3E](https://lists.apache.org/thread.html/r17aaa3a05b5b7fe9075613dd0c681efa60a4f8c8fbad152c61371b6e%2540%3Cusers.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/r38a5b7943b9a62ecb853acc22ef08ff586a7b3c66e08f949f0396ab1%40%3Cusers.tomcat.apache.org%3E](https://lists.apache.org/thread.html/r38a5b7943b9a62ecb853acc22ef08ff586a7b3c66e08f949f0396ab1%2540%3Cusers.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/r43faacf64570b1d9a4bada407a5af3b2738b0c007b905f1b6b608c65%40%3Cusers.tomcat.apache.org%3E](https://lists.apache.org/thread.html/r43faacf64570b1d9a4bada407a5af3b2738b0c007b905f1b6b608c65%2540%3Cusers.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/r4afa11e0464408e68f0e9560e90b185749363a66398b1491254f7864%40%3Cusers.tomcat.apache.org%3E](https://lists.apache.org/thread.html/r4afa11e0464408e68f0e9560e90b185749363a66398b1491254f7864%2540%3Cusers.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/r4f86cb260196e5cfcbbe782822c225ddcc70f54560f14a8f11c6926f%40%3Cusers.tomcat.apache.org%3E](https://lists.apache.org/thread.html/r4f86cb260196e5cfcbbe782822c225ddcc70f54560f14a8f11c6926f%2540%3Cusers.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/r549b43509e387a42656f0641fa311bf27c127c244fe02007d5b8d6f6%40%3Cdev.tomcat.apache.org%3E](https://lists.apache.org/thread.html/r549b43509e387a42656f0641fa311bf27c127c244fe02007d5b8d6f6%2540%3Cdev.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/r5e2f1201b92ee05a0527cfc076a81ea0c270be299b87895c0ddbe02b%40%3Cusers.tomcat.apache.org%3E](https://lists.apache.org/thread.html/r5e2f1201b92ee05a0527cfc076a81ea0c270be299b87895c0ddbe02b%2540%3Cusers.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/r61f280a76902b594692f0b24a1dbf647bb5a4c197b9395e9a6796e7c%40%3Cusers.tomcat.apache.org%3E](https://lists.apache.org/thread.html/r61f280a76902b594692f0b24a1dbf647bb5a4c197b9395e9a6796e7c%2540%3Cusers.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/r6a5633cad1b560a1e51f5b425f02918bdf30e090fdf18c5f7c2617eb%40%3Ccommits.tomee.apache.org%3E](https://lists.apache.org/thread.html/r6a5633cad1b560a1e51f5b425f02918bdf30e090fdf18c5f7c2617eb%2540%3Ccommits.tomee.apache.org%3E)
- [https://lists.apache.org/thread.html/r74328b178f9f37fe759dffbc9c1f2793e66d79d7a8a20d3836551794%40%3Cnotifications.ofbiz.apache.org%3E](https://lists.apache.org/thread.html/r74328b178f9f37fe759dffbc9c1f2793e66d79d7a8a20d3836551794%2540%3Cnotifications.ofbiz.apache.org%3E)
- [https://lists.apache.org/thread.html/r75113652e46c4dee687236510649acfb70d2c63e074152049c3f399d%40%3Cnotifications.ofbiz.apache.org%3E](https://lists.apache.org/thread.html/r75113652e46c4dee687236510649acfb70d2c63e074152049c3f399d%2540%3Cnotifications.ofbiz.apache.org%3E)
- [https://lists.apache.org/thread.html/r772335e6851ad33ddb076218fa4ff70de1bf398d5b43e2ddf0130e5d%40%3Cdev.tomcat.apache.org%3E](https://lists.apache.org/thread.html/r772335e6851ad33ddb076218fa4ff70de1bf398d5b43e2ddf0130e5d%2540%3Cdev.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/r7c6f492fbd39af34a68681dbbba0468490ff1a97a1bd79c6a53610ef%40%3Cannounce.tomcat.apache.org%3E](https://lists.apache.org/thread.html/r7c6f492fbd39af34a68681dbbba0468490ff1a97a1bd79c6a53610ef%2540%3Cannounce.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/r856cdd87eda7af40b50278d6de80ee4b42d63adeb433a34a7bdaf9db%40%3Cnotifications.ofbiz.apache.org%3E](https://lists.apache.org/thread.html/r856cdd87eda7af40b50278d6de80ee4b42d63adeb433a34a7bdaf9db%2540%3Cnotifications.ofbiz.apache.org%3E)
- [https://lists.apache.org/thread.html/r8f7484589454638af527182ae55ef5b628ba00c05c5b11887c922fb1%40%3Cnotifications.ofbiz.apache.org%3E](https://lists.apache.org/thread.html/r8f7484589454638af527182ae55ef5b628ba00c05c5b11887c922fb1%2540%3Cnotifications.ofbiz.apache.org%3E)
- [https://lists.apache.org/thread.html/r9f119d9ce9239114022e13dbfe385b3de7c972f24f05d6dbd35c1a2f%40%3Cusers.tomcat.apache.org%3E](https://lists.apache.org/thread.html/r9f119d9ce9239114022e13dbfe385b3de7c972f24f05d6dbd35c1a2f%2540%3Cusers.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/ra7092f7492569b39b04ec0decf52628ba86c51f15efb38f5853e2760%40%3Cnotifications.ofbiz.apache.org%3E](https://lists.apache.org/thread.html/ra7092f7492569b39b04ec0decf52628ba86c51f15efb38f5853e2760%2540%3Cnotifications.ofbiz.apache.org%3E)
- [https://lists.apache.org/thread.html/rad36ec6a1ffc9e43266b030c22ceeea569243555d34fb4187ff08522%40%3Cnotifications.ofbiz.apache.org%3E](https://lists.apache.org/thread.html/rad36ec6a1ffc9e43266b030c22ceeea569243555d34fb4187ff08522%2540%3Cnotifications.ofbiz.apache.org%3E)
- [https://lists.apache.org/thread.html/rb1c0fb105ce2b93b7ec6fc1b77dd208022621a91c12d1f580813cfed%40%3Cdev.tomcat.apache.org%3E](https://lists.apache.org/thread.html/rb1c0fb105ce2b93b7ec6fc1b77dd208022621a91c12d1f580813cfed%2540%3Cdev.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/rb2fc890bef23cbc7f343900005fe1edd3b091cf18dada455580258f9%40%3Cusers.tomcat.apache.org%3E](https://lists.apache.org/thread.html/rb2fc890bef23cbc7f343900005fe1edd3b091cf18dada455580258f9%2540%3Cusers.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/rbdb1d2b651a3728f0ceba9e0853575b6f90296a94a71836a15f7364a%40%3Cdev.tomee.apache.org%3E](https://lists.apache.org/thread.html/rbdb1d2b651a3728f0ceba9e0853575b6f90296a94a71836a15f7364a%2540%3Cdev.tomee.apache.org%3E)
- [https://lists.apache.org/thread.html/rc068e824654c4b8bd4f2490bec869e29edbfcd5dfe02d47cbf7433b2%40%3Cdev.tomee.apache.org%3E](https://lists.apache.org/thread.html/rc068e824654c4b8bd4f2490bec869e29edbfcd5dfe02d47cbf7433b2%2540%3Cdev.tomee.apache.org%3E)
- [https://lists.apache.org/thread.html/rcd5cd301e9e7e39f939baf2f5d58704750be07a5e2d3393e40ca7194%40%3Ccommits.tomee.apache.org%3E](https://lists.apache.org/thread.html/rcd5cd301e9e7e39f939baf2f5d58704750be07a5e2d3393e40ca7194%2540%3Ccommits.tomee.apache.org%3E)
- [https://lists.apache.org/thread.html/rce2af55f6e144ffcdc025f997eddceb315dfbc0b230e3d750a7f7425%40%3Cnotifications.ofbiz.apache.org%3E](https://lists.apache.org/thread.html/rce2af55f6e144ffcdc025f997eddceb315dfbc0b230e3d750a7f7425%2540%3Cnotifications.ofbiz.apache.org%3E)
- [https://lists.apache.org/thread.html/rd0774c95699d5aeb5e16e9a600fb2ea296e81175e30a62094e27e3e7%40%3Ccommits.ofbiz.apache.org%3E](https://lists.apache.org/thread.html/rd0774c95699d5aeb5e16e9a600fb2ea296e81175e30a62094e27e3e7%2540%3Ccommits.ofbiz.apache.org%3E)
- [https://lists.apache.org/thread.html/rd50baccd1bbb96c2327d5a8caa25a49692b3d68d96915bd1cfbb9f8b%40%3Cusers.tomcat.apache.org%3E](https://lists.apache.org/thread.html/rd50baccd1bbb96c2327d5a8caa25a49692b3d68d96915bd1cfbb9f8b%2540%3Cusers.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/re5eecbe5bf967439bafeeaa85987b3a43f0e6efe06b6976ee768cde2%40%3Cusers.tomcat.apache.org%3E](https://lists.apache.org/thread.html/re5eecbe5bf967439bafeeaa85987b3a43f0e6efe06b6976ee768cde2%2540%3Cusers.tomcat.apache.org%3E)
- [https://lists.apache.org/thread.html/rf26663f42e7f1a1d1cac732469fb5e92c89908a48b61ec546dbb79ca%40%3Cbugs.httpd.apache.org%3E](https://lists.apache.org/thread.html/rf26663f42e7f1a1d1cac732469fb5e92c89908a48b61ec546dbb79ca%2540%3Cbugs.httpd.apache.org%3E)
- [https://lists.apache.org/thread.html/rf992c5adf376294af31378a70aa8a158388a41d7039668821be28df3%40%3Ccommits.tomee.apache.org%3E](https://lists.apache.org/thread.html/rf992c5adf376294af31378a70aa8a158388a41d7039668821be28df3%2540%3Ccommits.tomee.apache.org%3E)
- [https://lists.debian.org/debian-lts-announce/2020/03/msg00006.html](https://lists.debian.org/debian-lts-announce/2020/03/msg00006.html)
- [https://lists.debian.org/debian-lts-announce/2020/05/msg00026.html](https://lists.debian.org/debian-lts-announce/2020/05/msg00026.html)
- [https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2XFLQB3O5QVP4ZBIPVIXBEZV7F2R7ZMS/](https://lists.fedoraproject.org/archives/list/package-announce%2540lists.fedoraproject.org/message/2XFLQB3O5QVP4ZBIPVIXBEZV7F2R7ZMS/)
- [https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K3IPNHCKFVUKSHDTM45UL4Q765EHHTFG/](https://lists.fedoraproject.org/archives/list/package-announce%2540lists.fedoraproject.org/message/K3IPNHCKFVUKSHDTM45UL4Q765EHHTFG/)
- [https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L46WJIV6UV3FWA5O5YEY6XLA73RYD53B/](https://lists.fedoraproject.org/archives/list/package-announce%2540lists.fedoraproject.org/message/L46WJIV6UV3FWA5O5YEY6XLA73RYD53B/)
- [https://security.gentoo.org/glsa/202003-43](https://security.gentoo.org/glsa/202003-43)
- [https://www.debian.org/security/2020/dsa-4673](https://www.debian.org/security/2020/dsa-4673)
- [https://www.debian.org/security/2020/dsa-4680](https://www.debian.org/security/2020/dsa-4680)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2020-1938 · Markdown: https://rewindex.com/cve/CVE-2020-1938.md · JSON: https://rewindex.com/api/v1/cves/CVE-2020-1938 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:12:36.964Z