--- title: "CVE-2020-1938: Apache Tomcat vulnerability | CubePath" description: "When using the Apache JServ Protocol (AJP), care must be taken when trusting incoming connections to Apache Tomcat. Tomcat treats AJP connections…" language: en source: https://cubepath.com/security/cve/CVE-2020-1938 --- # CVE-2020-1938: Apache Tomcat vulnerability | CubePath ## 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. Official description from the CVE record, published by apache. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2020-1938) ## Key data ### CVSS 3.1 Critical 9.8 Score published by CISA-ADP in the CVE record. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | Metric | Value | What it means | | ---------------------- | --------- | ----------------------------------------------------------------------------------- | | Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. | | Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. | | Privileges required | None | No account or privileges are needed. | | User interaction | None | No action from any user is needed. | | Scope | Unchanged | The impact stays within the vulnerable component. | | Confidentiality impact | High | Serious or total effect on the secrecy of data. | | Integrity impact | High | Serious or total effect on the trustworthiness of data. | | Availability impact | High | Serious or total effect on availability. | CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) . ### EPSS Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days. Score 0.99270 (99.3% probability) Percentile 99.9% Scores of Nov 10, 2026 Model v2026.06.15 ### CISA Known Exploited Vulnerabilities This CVE is listed in the CISA KEV catalog. Name in the catalog Apache Tomcat Improper Privilege Management Vulnerability Added to the catalog Mar 3, 2022 Federal due date Mar 17, 2022 ### CISA assessment as of Feb 6, 2025 Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA. Exploitation Recorded by CISA as active Automatable yes Technical impact total ## Affected products Products listed in the CVE record, as the CNA published them. - 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 ## References Links listed in the CVE record. They lead to other sites, which CubePath does not control. - [\[tomcat-announce\] 20200224 \[SECURITY\] CVE-2020-1938 AJP Request Injection and potential Remote Code Execution](https://lists.apache.org/thread.html/r7c6f492fbd39af34a68681dbbba0468490ff1a97a1bd79c6a53610ef%40%3Cannounce.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[ofbiz-notifications\] 20200225 \[jira\] \[Commented\] (OFBIZ-11407) Upgrade Tomcat from 9.0.29 to 9.0.31 (CVE-2020-1938)](https://lists.apache.org/thread.html/r856cdd87eda7af40b50278d6de80ee4b42d63adeb433a34a7bdaf9db%40%3Cnotifications.ofbiz.apache.org%3E) (lists.apache.org) mailing-list - [\[ofbiz-notifications\] 20200225 \[jira\] \[Updated\] (OFBIZ-11407) Upgrade Tomcat from 9.0.29 to 9.0.31 (CVE-2020-1938)](https://lists.apache.org/thread.html/r75113652e46c4dee687236510649acfb70d2c63e074152049c3f399d%40%3Cnotifications.ofbiz.apache.org%3E) (lists.apache.org) mailing-list - [\[ofbiz-commits\] 20200227 \[ofbiz-plugins\] branch release17.12 updated: Upgrade Tomcat from 9.0.29 to 9.0.31 (CVE-2020-1938) (OFBIZ-11407)](https://lists.apache.org/thread.html/rd0774c95699d5aeb5e16e9a600fb2ea296e81175e30a62094e27e3e7%40%3Ccommits.ofbiz.apache.org%3E) (lists.apache.org) mailing-list - [\[ofbiz-notifications\] 20200227 \[jira\] \[Commented\] (OFBIZ-11407) Upgrade Tomcat from 9.0.29 to 9.0.31 (CVE-2020-1938)](https://lists.apache.org/thread.html/r74328b178f9f37fe759dffbc9c1f2793e66d79d7a8a20d3836551794%40%3Cnotifications.ofbiz.apache.org%3E) (lists.apache.org) mailing-list - [\[ofbiz-notifications\] 20200228 \[jira\] \[Commented\] (OFBIZ-11407) Upgrade Tomcat from 9.0.29 to 9.0.31 (CVE-2020-1938)](https://lists.apache.org/thread.html/rce2af55f6e144ffcdc025f997eddceb315dfbc0b230e3d750a7f7425%40%3Cnotifications.ofbiz.apache.org%3E) (lists.apache.org) mailing-list - [\[ofbiz-notifications\] 20200228 \[jira\] \[Comment Edited\] (OFBIZ-11407) Upgrade Tomcat from 9.0.29 to 9.0.31 (CVE-2020-1938)](https://lists.apache.org/thread.html/rad36ec6a1ffc9e43266b030c22ceeea569243555d34fb4187ff08522%40%3Cnotifications.ofbiz.apache.org%3E) (lists.apache.org) mailing-list - [\[tomcat-users\] 20200301 Re: \[SECURITY\] CVE-2020-1938 AJP Request Injection and potential Remote Code Execution](https://lists.apache.org/thread.html/rb2fc890bef23cbc7f343900005fe1edd3b091cf18dada455580258f9%40%3Cusers.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[tomcat-users\] 20200302 Re: AW: \[SECURITY\] CVE-2020-1938 AJP Request Injection and potentialRemote Code Execution](https://lists.apache.org/thread.html/r38a5b7943b9a62ecb853acc22ef08ff586a7b3c66e08f949f0396ab1%40%3Cusers.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[tomcat-users\] 20200302 AW: \[SECURITY\] CVE-2020-1938 AJP Request Injection and potentialRemote Code Execution](https://lists.apache.org/thread.html/r17aaa3a05b5b7fe9075613dd0c681efa60a4f8c8fbad152c61371b6e%40%3Cusers.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[tomcat-users\] 20200302 Re: \[SECURITY\] CVE-2020-1938 AJP Request Injection and potential Remote Code Execution](https://lists.apache.org/thread.html/rd50baccd1bbb96c2327d5a8caa25a49692b3d68d96915bd1cfbb9f8b%40%3Cusers.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[tomcat-users\] 20200304 Re: Fix for CVE-2020-1938](https://lists.apache.org/thread.html/r4afa11e0464408e68f0e9560e90b185749363a66398b1491254f7864%40%3Cusers.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[tomcat-dev\] 20200304 Re: Tagging 10.0.x, 9.0.x, 8.5.x](https://lists.apache.org/thread.html/r772335e6851ad33ddb076218fa4ff70de1bf398d5b43e2ddf0130e5d%40%3Cdev.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[debian-lts-announce\] 20200304 \[SECURITY\] \[DLA 2133-1\] tomcat7 security update](https://lists.debian.org/debian-lts-announce/2020/03/msg00006.html) (lists.debian.org) mailing-list - [\[tomcat-users\] 20200305 Aw: Re: Fix for CVE-2020-1938](https://lists.apache.org/thread.html/re5eecbe5bf967439bafeeaa85987b3a43f0e6efe06b6976ee768cde2%40%3Cusers.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[tomcat-users\] 20200305 Re: Aw: Re: Fix for CVE-2020-1938](https://lists.apache.org/thread.html/r5e2f1201b92ee05a0527cfc076a81ea0c270be299b87895c0ddbe02b%40%3Cusers.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[tomcat-dev\] 20200309 \[Bug 64206\] Answer file not being used](https://lists.apache.org/thread.html/r549b43509e387a42656f0641fa311bf27c127c244fe02007d5b8d6f6%40%3Cdev.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[tomcat-users\] 20200309 Re: Apache Tomcat AJP File Inclusion Vulnerability (unauthenticated check)](https://lists.apache.org/thread.html/r61f280a76902b594692f0b24a1dbf647bb5a4c197b9395e9a6796e7c%40%3Cusers.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[tomcat-users\] 20200310 Aw: Re: Re: Fix for CVE-2020-1938](https://lists.apache.org/thread.html/r4f86cb260196e5cfcbbe782822c225ddcc70f54560f14a8f11c6926f%40%3Cusers.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[tomcat-users\] 20200310 Re: Re: Re: Fix for CVE-2020-1938](https://lists.apache.org/thread.html/r9f119d9ce9239114022e13dbfe385b3de7c972f24f05d6dbd35c1a2f%40%3Cusers.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[tomee-dev\] 20200311 CVE-2020-1938 on Tomcat 9.0.30 / TomEE 8.0.1](https://lists.apache.org/thread.html/r089dc67c0358a1556dd279c762c74f32d7a254a54836b7ee2d839d8e%40%3Cdev.tomee.apache.org%3E) (lists.apache.org) mailing-list - [\[tomee-dev\] 20200311 Re: CVE-2020-1938 on Tomcat 9.0.30 / TomEE 8.0.1](https://lists.apache.org/thread.html/rbdb1d2b651a3728f0ceba9e0853575b6f90296a94a71836a15f7364a%40%3Cdev.tomee.apache.org%3E) (lists.apache.org) mailing-list - [openSUSE-SU-2020:0345](http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00025.html) (lists.opensuse.org) vendor-advisory - [\[tomee-dev\] 20200316 RE: CVE-2020-8840 on TomEE 8.0.1](https://lists.apache.org/thread.html/rc068e824654c4b8bd4f2490bec869e29edbfcd5dfe02d47cbf7433b2%40%3Cdev.tomee.apache.org%3E) (lists.apache.org) mailing-list - [\[httpd-bugs\] 20200319 \[Bug 53098\] mod\_proxy\_ajp: patch to set worker secret passed to tomcat](https://lists.apache.org/thread.html/rf26663f42e7f1a1d1cac732469fb5e92c89908a48b61ec546dbb79ca%40%3Cbugs.httpd.apache.org%3E) (lists.apache.org) mailing-list - [GLSA-202003-43](https://security.gentoo.org/glsa/202003-43) (security.gentoo.org) vendor-advisory - [\[tomee-commits\] 20200320 \[jira\] \[Updated\] (TOMEE-2789) TomEE plus(7.0.7) is affected by CVE-2020-1938(BDSA-2020-0339) vulnerability.](https://lists.apache.org/thread.html/rcd5cd301e9e7e39f939baf2f5d58704750be07a5e2d3393e40ca7194%40%3Ccommits.tomee.apache.org%3E) (lists.apache.org) mailing-list - [\[tomee-commits\] 20200320 \[jira\] \[Created\] (TOMEE-2789) TomEE plus is affected by CVE-2020-1938(BDSA-2020-0339) vulnerability.](https://lists.apache.org/thread.html/rf992c5adf376294af31378a70aa8a158388a41d7039668821be28df3%40%3Ccommits.tomee.apache.org%3E) (lists.apache.org) mailing-list - [\[tomee-commits\] 20200323 \[jira\] \[Commented\] (TOMEE-2789) TomEE plus(7.0.7) is affected by CVE-2020-1938(BDSA-2020-0339) vulnerability.](https://lists.apache.org/thread.html/r6a5633cad1b560a1e51f5b425f02918bdf30e090fdf18c5f7c2617eb%40%3Ccommits.tomee.apache.org%3E) (lists.apache.org) mailing-list - [FEDORA-2020-0e42878ba7](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2XFLQB3O5QVP4ZBIPVIXBEZV7F2R7ZMS/) (lists.fedoraproject.org) vendor-advisory - [FEDORA-2020-c870aa8378](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L46WJIV6UV3FWA5O5YEY6XLA73RYD53B/) (lists.fedoraproject.org) vendor-advisory - [FEDORA-2020-04ac174fa9](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K3IPNHCKFVUKSHDTM45UL4Q765EHHTFG/) (lists.fedoraproject.org) vendor-advisory - [\[tomcat-users\] 20200413 RE: Alternatives for AJP](https://lists.apache.org/thread.html/r43faacf64570b1d9a4bada407a5af3b2738b0c007b905f1b6b608c65%40%3Cusers.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [openSUSE-SU-2020:0597](http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00002.html) (lists.opensuse.org) vendor-advisory - [DSA-4673](https://www.debian.org/security/2020/dsa-4673) (debian.org) vendor-advisory - [DSA-4680](https://www.debian.org/security/2020/dsa-4680) (debian.org) vendor-advisory - [\[debian-lts-announce\] 20200528 \[SECURITY\] \[DLA 2209-1\] tomcat8 security update](https://lists.debian.org/debian-lts-announce/2020/05/msg00026.html) (lists.debian.org) mailing-list - [\[tomcat-dev\] 20200625 svn commit: r1879208 - in /tomcat/site/trunk: docs/security-10.html docs/security-8.html docs/security-9.html xdocs/security-10.xml xdocs/security-8.xml xdocs/security-9.xml](https://lists.apache.org/thread.html/rb1c0fb105ce2b93b7ec6fc1b77dd208022621a91c12d1f580813cfed%40%3Cdev.tomcat.apache.org%3E) (lists.apache.org) mailing-list - [\[ofbiz-notifications\] 20200628 \[jira\] \[Updated\] (OFBIZ-11847) CLONE - Upgrade Tomcat from 9.0.34 to 9.0.36 (CVE-2020-11996)](https://lists.apache.org/thread.html/ra7092f7492569b39b04ec0decf52628ba86c51f15efb38f5853e2760%40%3Cnotifications.ofbiz.apache.org%3E) (lists.apache.org) mailing-list - [\[ofbiz-notifications\] 20200628 \[jira\] \[Created\] (OFBIZ-11847) CLONE - Upgrade Tomcat from 9.0.34 to 9.0.36 (CVE-2020-11996)](https://lists.apache.org/thread.html/r8f7484589454638af527182ae55ef5b628ba00c05c5b11887c922fb1%40%3Cnotifications.ofbiz.apache.org%3E) (lists.apache.org) mailing-list - [oracle.com/security-alerts/cpujul2020.html](https://www.oracle.com/security-alerts/cpujul2020.html) - [security.netapp.com/advisory/ntap-20200226-0002](https://security.netapp.com/advisory/ntap-20200226-0002/) - [support.blackberry.com/kb/articleDetail?articleNumber=00006…](http://support.blackberry.com/kb/articleDetail?articleNumber=000062739) - [\[tomee-users\] 20200723 Re: TomEE on Docker](https://lists.apache.org/thread.html/r92d78655c068d0bc991d1edbdfb24f9c5134603e647cade1113d4e0a%40%3Cusers.tomee.apache.org%3E) (lists.apache.org) mailing-list - [\[geode-issues\] 20200831 \[jira\] \[Created\] (GEODE-8471) Dependency security issues in geode-core-1.12](https://lists.apache.org/thread.html/rf1bbc0ea4a9f014cf94df9a12a6477d24a27f52741dbc87f2fd52ff2%40%3Cissues.geode.apache.org%3E) (lists.apache.org) mailing-list - [oracle.com/security-alerts/cpuoct2020.html](https://www.oracle.com/security-alerts/cpuoct2020.html) - [\[tomee-commits\] 20201127 \[jira\] \[Resolved\] (TOMEE-2789) TomEE plus(7.0.7) is affected by CVE-2020-1938(BDSA-2020-0339) vulnerability.](https://lists.apache.org/thread.html/r57f5e4ced436ace518a9e222fabe27fb785f09f5bf974814cc48ca97%40%3Ccommits.tomee.apache.org%3E) (lists.apache.org) mailing-list - [\[tomee-commits\] 20201127 \[jira\] \[Updated\] (TOMEE-2789) TomEE plus(7.0.7) is affected by CVE-2020-1938(BDSA-2020-0339) vulnerability.](https://lists.apache.org/thread.html/r47caef01f663106c2bb81d116b8380d62beac9e543dd3f3bc2c2beda%40%3Ccommits.tomee.apache.org%3E) (lists.apache.org) mailing-list - [oracle.com/security-alerts/cpujan2021.html](https://www.oracle.com/security-alerts/cpujan2021.html) - [\[announce\] 20210125 Apache Software Foundation Security Report: 2020](https://lists.apache.org/thread.html/r90890afea72a9571d666820b2fe5942a0a5f86be406fa31da3dd0922%40%3Cannounce.apache.org%3E) (lists.apache.org) mailing-list - [\[announce\] 20210223 Re: Apache Software Foundation Security Report: 2020](https://lists.apache.org/thread.html/r1125f3044a0946d1e7e6f125a6170b58d413ebd4a95157e4608041c7%40%3Cannounce.apache.org%3E) (lists.apache.org) mailing-list ## Timeline 1. ID reserved Dec 2, 2019 2. Record published Feb 24, 2020 3. Added to CISA KEV Mar 3, 2022 4. Record last updated Oct 21, 2025 ## Look up another CVE ## About CubePath CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection. [Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection) Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:33 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)