CVE-2023-45648

Apache Tomcat: Trailer header parsing too lenient

MEDIUM
5.3
CVSS Score
Published: October 10, 2023 at 06:38 PM UTC
Updated: June 17, 2026 at 06:28 AM UTC
2 products affected across 2 vendorsDebian LinuxTomcat

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Severity
MEDIUM5.3
Exploit prediction
EPSS 6%
SSVC
No known exploit

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Affected range stops below 10.1.14, so it looks safe — our inference, not a vendor statement
Affected range stops below 8.5.94, so it looks safe — our inference, not a vendor statement
Affected range stops below 9.0.81, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 10.0.0-M1 (unknown)
Vendor states this is fixed in 3 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (6)

Mailing ListThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
http://www.openwall.com/lists/oss-security/2023/10/10/10
Mailing ListThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.debian.org/debian-lts-announce/2023/10/msg00020.html
Source: af854a3a-2127-422b-91ae-364da2661108
https://security.netapp.com/advisory/ntap-20231103-0007/
Third Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
https://www.debian.org/security/2023/dsa-5521
Third Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
https://www.debian.org/security/2023/dsa-5522

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-20NVD-CWE-Other

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