Actively exploited · Published Feb 24, 2020 · Assigned by apache

CVE-2020-1938

Critical 9.8 Exploited

In plain English

A critical-severity security flaw in Apache Tomcat from Apache. Attackers are actively exploiting it in the wild (listed by CISA on March 3, 2022). The chance it is exploited in the next 30 days is estimated at 99.3% (higher than 99.9% of all known vulnerabilities). Ready-made attack tooling exists: Metasploit, Nuclei, public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)99.3%top 0.1% of all CVEs
Exploited in the wildYesCISA KEV since Mar 3, 2022
Attack tooling3Metasploit, Nuclei, Public PoC

CISA guidance

Apply updates per vendor instructions.

Federal agencies must remediate by Mar 17, 2022.

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12tomcat99.0.31-1DEBIAN-CVE-2020-1938
Debian:13tomcat99.0.31-1DEBIAN-CVE-2020-1938
Debian:14tomcat99.0.31-1DEBIAN-CVE-2020-1938
Mavenorg.apache.tomcat.embed:tomcat-embed-core8.5.51GHSA-c9hw-wf7x-jp9j
Mavenorg.apache.tomcat.embed:tomcat-embed-core9.0.31GHSA-c9hw-wf7x-jp9j
Mavenorg.apache.tomcat.embed:tomcat-embed-core7.0.100GHSA-c9hw-wf7x-jp9j
Rocky Linux:8apache-commons-collections0:3.2.2-10.module+el8.3.0+74+855e3f5dRLSA-2020:4847
Rocky Linux:8apache-commons-collections0:3.2.2-10.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8apache-commons-lang0:2.6-21.module+el8.3.0+74+855e3f5dRLSA-2020:4847
Rocky Linux:8apache-commons-lang0:2.6-21.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8apache-commons-net0:3.6-3.module+el8.3.0+74+855e3f5dRLSA-2020:4847
Rocky Linux:8apache-commons-net0:3.6-3.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8bea-stax0:1.2.0-16.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8glassfish-fastinfoset0:1.2.13-9.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8glassfish-jaxb0:2.2.11-11.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8glassfish-jaxb-api0:2.2.12-8.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8jackson-annotations0:2.10.0-1.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8jackson-core0:2.10.0-1.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8jackson-databind0:2.10.0-1.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8jackson-jaxrs-providers0:2.9.9-1.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8jackson-module-jaxb-annotations0:2.7.6-4.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8jakarta-commons-httpclient1:3.1-28.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8jakarta-commons-httpclient1:3.1-28.module+el8.3.0+74+855e3f5dRLSA-2020:4847
Rocky Linux:8javassist0:3.18.1-8.module+el8.3.0+74+855e3f5dRLSA-2020:4847
Rocky Linux:8javassist0:3.18.1-8.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8ldapjdk0:4.22.0-1.module+el8.4.0+418+b7ae1d4aRLSA-2020:4847
Rocky Linux:8pki-servlet-engine1:9.0.30-1.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8python-nss0:1.0.1-10.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8relaxngDatatype0:2011.1-7.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8resteasy0:3.0.26-3.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8slf4j0:1.7.25-4.module+el8.3.0+133+b8b54b58RLSA-2020:4847
Rocky Linux:8slf4j0:1.7.25-4.module+el8.3.0+74+855e3f5dRLSA-2020:4847
Rocky Linux:8slf4j0:1.7.25-4.module+el8.5.0+697+f586bb30RLSA-2020:4847
Rocky Linux:8stax-ex0:1.7.7-8.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8velocity0:1.7-24.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8velocity0:1.7-24.module+el8.3.0+74+855e3f5dRLSA-2020:4847
Rocky Linux:8xalan-j20:2.7.1-38.module+el8.3.0+74+855e3f5dRLSA-2020:4847
Rocky Linux:8xalan-j20:2.7.1-38.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8xerces-j20:2.11.0-34.module+el8.3.0+74+855e3f5dRLSA-2020:4847
Rocky Linux:8xerces-j20:2.11.0-34.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8xml-commons-apis0:1.4.01-25.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8xml-commons-apis0:1.4.01-25.module+el8.3.0+74+855e3f5dRLSA-2020:4847
Rocky Linux:8xml-commons-apis0:1.4.01-25.module+el8.5.0+697+f586bb30RLSA-2020:4847
Rocky Linux:8xml-commons-resolver0:1.2-26.module+el8.3.0+74+855e3f5dRLSA-2020:4847
Rocky Linux:8xml-commons-resolver0:1.2-26.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8xmlstreambuffer0:1.5.4-8.module+el8.3.0+53+ea062990RLSA-2020:4847
Rocky Linux:8xsom0:0-19.20110809svn.module+el8.3.0+53+ea062990RLSA-2020:4847

Affected products (as reported)

VendorProductVersions
Apache Apache Tomcat Apache Tomcat 9.0.0.M1 to 9.0.0.308.5.0 to 8.5.507.0.0 to 7.0.99

References