cbcvebase.
CVE-2020-1938
published 2020-02-24

CVE-2020-1938: When using the Apache JServ Protocol (AJP), care must be taken when trusting incoming connections to Apache Tomcat. Tomcat treats AJP connections as having…

PriorityP197critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
KEVITWEXPLOITInitial access
CISA Known Exploited Vulnerabilitydue 2022-03-17
Exploited in the wild
EPSS
99.27%
99.9th percentile
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

43 ranges· showing 25
VendorProductVersion rangeFixed in
apacheapache_tomcat
apacheapache_tomcat
apacheapache_tomcat
apachegeode
apachetomcat
apachetomcat>= 7.0.0 < 7.0.1007.0.100
apachetomcat>= 8.5.0 < 8.5.518.5.51
apachetomcat>= 9.0.0 < 9.0.319.0.31
blackberrygood_control<= 5.2.58.38
blackberryworkspaces_server
blackberryworkspaces_server
blackberryworkspaces_server
blackberryworkspaces_server
debiandebian_linux
debiandebian_linux
debiandebian_linux
debiantomcat9< tomcat9 9.0.31-1 (bookworm)tomcat9 9.0.31-1 (bookworm)
fedoraprojectfedora
fedoraprojectfedora
fedoraprojectfedora
netapponcommand_system_manager3.0.0 – 3.1.3
opensuseleap
oracleagile_engineering_data_management
oracleagile_plm
oracleagile_plm

Detection & IOCsextracted from sources · hover to see the quote

port8009
path/conf/server.xml
  • Monitor for inbound connections to TCP port 8009 (AJP connector) from untrusted/external sources, which is the default attack vector for CVE-2020-1938.
  • Check Point IPS signature 'Apache Tomcat AJP File Inclusion (CVE-2020-1938)' can be used for network-level detection.
  • For RCE scenario, look for file uploads combined with AJP requests referencing uploaded files within the web application document root (e.g., webapps/APP/...).
  • Detect vulnerable Tomcat instances by querying asset inventory for Tomcat versions 9.0.0–9.0.30, 8.5.0–8.5.50, 7.0.0–7.0.99, and any 6.x version.
  • Malicious JSP code can be embedded within a variety of file types and uploaded, then triggered via the AJP connector to achieve RCE — inspect uploaded files for JSP content regardless of file extension.
  • ·The AJP connector is enabled by default in Tomcat 6, 7, 8, and 9; exploitation requires the AJP port (8009) to be reachable. RCE is only possible if the application also allows file uploads saved within the document root — it is NOT a default RCE vulnerability.
  • ·SysAid On-Premise 20.1.11 exposes the AJP port by default AND allows unauthenticated file uploads, making it a chained RCE scenario distinct from a standard Tomcat deployment.
  • ·Apache Tomcat 6.x is also affected but has no available patch; users must upgrade to a supported version.

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
osv9.8CRITICAL
vulncheck9.8CRITICAL
cisa9.8CRITICAL
vendor_apache9.8CRITICAL
vendor_debian9.8CRITICAL
vendor_oracle9.8CRITICAL
vendor_redhat9.8CRITICAL
CVEs like this are exactly what “Exploited This Week” covers.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.