cbcvebase.
CVE-2023-45648
published 2023-10-10

CVE-2023-45648: Improper Input Validation vulnerability in Apache Tomcat.Tomcat from 11.0.0-M1 through 11.0.0-M11, from 10.1.0-M1 through 10.1.13, from 9.0.0-M1 through 9.0.81…

PriorityP343medium5.3CVSS 3.1
AVNACLPRNUINSUCNILAN
EXPLOIT
EPSS
5.85%
92.3th percentile
Improper Input Validation vulnerability in Apache Tomcat.Tomcat from 11.0.0-M1 through 11.0.0-M11, from 10.1.0-M1 through 10.1.13, from 9.0.0-M1 through 9.0.81 and from 8.5.0 through 8.5.93 did not correctly parse HTTP trailer headers. A specially crafted, invalid trailer header could cause Tomcat to treat a single request as multiple requests leading to the possibility of request smuggling when behind a reverse proxy. Older, EOL versions may also be affected. Users are recommended to upgrade to version 11.0.0-M12 onwards, 10.1.14 onwards, 9.0.81 onwards or 8.5.94 onwards, which fix the issue.

Affected

16 ranges
VendorProductVersion rangeFixed in
apachetomcat
apachetomcat
apachetomcat
apachetomcat
apachetomcat>= 10.1.1 < 10.1.1410.1.14
apachetomcat>= 8.5.0 < 8.5.948.5.94
apachetomcat>= 9.0.1 < 9.0.819.0.81
apache_software_foundationapache_tomcat10.1.0-M1 – 10.1.13
apache_software_foundationapache_tomcat11.0.0-M1 – 11.0.0-M11
apache_software_foundationapache_tomcat8.5.0 – 8.5.93
apache_software_foundationapache_tomcat9.0.0-M1 – 9.0.81
debiandebian_linux
debiandebian_linux
debiandebian_linux
debiantomcat10< tomcat10 10.1.6-1+deb12u1 (bookworm)tomcat10 10.1.6-1+deb12u1 (bookworm)
debiantomcat9< tomcat10 10.1.6-1+deb12u1 (bookworm)tomcat10 10.1.6-1+deb12u1 (bookworm)

Detection & IOCsextracted from sources · hover to see the quote

otherApache Tomcat/([0-9.]+(-M[0-9]+)?)
  • The attack vector is a specially crafted, invalid HTTP trailer header that causes Tomcat to treat a single request as multiple requests (request smuggling). Detection should focus on malformed or unexpected trailer headers in HTTP/1.1 chunked-encoding requests forwarded through a reverse proxy.
  • Shodan query 'title:"Apache Tomcat"' and FOFA query 'app="APACHE-Tomcat"' can be used to identify internet-exposed Tomcat instances for version-based triage.
  • The fix was introduced in commit 59583245 for the 8.5.x branch. Absence of this commit in a deployed Tomcat instance confirms vulnerability.
  • Qualys WAS QID 150732 detects vulnerable Apache Tomcat versions for CVE-2023-45648 (alongside CVE-2023-42795 and CVE-2023-44487) based on installed version.
  • ·Exploitation requires the Tomcat instance to be deployed behind a reverse proxy. A standalone Tomcat deployment without a reverse proxy in front is not exploitable for request smuggling via this vulnerability.
  • ·The request smuggling is not guaranteed to carry sensitive data in every smuggled request, and the reverse proxy must also fail to handle the malformed request correctly, reducing real-world exploitability.
  • ·Older, end-of-life Tomcat versions beyond the explicitly listed ranges may also be affected and should be treated as vulnerable.

CVSS provenance

nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
osv5.3MEDIUM
vendor_apache5.3MEDIUM
vendor_debian5.3MEDIUM
vendor_oracle5.3MEDIUM
vendor_redhat5.3MEDIUM
vendor_ubuntu4.3MEDIUM
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