IBM Support

Security Bulletin: CVE-2021-33037 Apache Tomcat 8.5.66 did not correctly parse the HTTP transfer-encoding request header leading to the possibility to request smuggling when used with a reverse proxy

Security Bulletin


Summary

Apache Tomcat 10.0.0-M1 to 10.0.6, 9.0.0.M1 to 9.0.46 and 8.5.0 to 8.5.66 did not correctly parse the HTTP transfer-encoding request header in some circumstances leading to the possibility to request smuggling when used with a reverse proxy. Specifically: - Tomcat incorrectly ignored the transfer encoding header if the client declared it would only accept an HTTP/1.0 response; - Tomcat honoured the identify encoding; and - Tomcat did not ensure that, if present, the chunked encoding was the final encoding.

Vulnerability Details

CVEID:   CVE-2021-33037
DESCRIPTION:   Apache Tomcat is vulnerable to HTTP request smuggling, caused by improper parsing of the HTTP transfer-encoding request header. By sending a specially-crafted HTTP(S) transfer-encoding request header, an attacker could exploit this vulnerability to poison the web cache, bypass web application firewall protection, and conduct XSS attacks.
CVSS Base score: 5.3
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/205222 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)

Affected Products and Versions

Affected Product(s)Version(s)
UCD - IBM UrbanCode Deploy7.1.1.1
UCD - IBM UrbanCode Deploy7.0.5.3
UCD - IBM UrbanCode Deploy7.1.1.2
UCD - IBM UrbanCode Deploy7.1.1.0
UCD - IBM UrbanCode Deploy7.1.0.0
UCD - IBM UrbanCode Deploy7.0.5.4
UCD - IBM UrbanCode Deploy6.2.7.4
UCD - IBM UrbanCode Deploy6.2.7.3
UCD - IBM UrbanCode Deploy6.2.7.8
UCD - IBM UrbanCode Deploy7.0.4.0
UCD - IBM UrbanCode Deploy6.2.7.9
UCD - IBM UrbanCode Deploy7.0.3.0
UCD - IBM UrbanCode DeployAll

Remediation/Fixes

Update to 7.2.0.2, 7.1.2.3, 7.0.5.7, 6.2.7.12 or later

Workarounds and Mitigations

None

Get Notified about Future Security Bulletins

References

Off

Change History

01 Sep 2021: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

Review the IBM security bulletin disclaimer and definitions regarding your responsibilities for assessing potential impact of security vulnerabilities to your environment.

Document Location

Worldwide

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SS4GSP","label":"IBM UrbanCode Deploy"},"Component":"","Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":" 7.2.0.2","Edition":"","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
01 September 2021

UID

ibm16485649