Vulnerability Database

383,371

Total vulnerabilities in the database

CVE-2023-45648 — org.apache.tomcat / tomcat

Improper Input Validation

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.

CVSS v3:

  • Severity: Medium
  • Score: 5.3
  • AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CWEs:

Software Affected versions
Maven icon org.apache.tomcat / tomcat >= 11.0.0-M1, < 11.0.0-M12
Maven icon org.apache.tomcat / tomcat >= 10.1.0-M1, < 10.1.14
Maven icon org.apache.tomcat / tomcat >= 9.0.0-M1, < 9.0.81
Maven icon org.apache.tomcat / tomcat >= 8.5.0, < 8.5.94
apache / tomcat >= 10.1.1, < 10.1.14
apache / tomcat >= 8.5.0, < 8.5.94
apache / tomcat >= 9.0.1, < 9.0.81
Maven icon org.apache.tomcat.embed / tomcat-embed-core >= 11.0.0-M1, < 11.0.0-M12
Maven icon org.apache.tomcat.embed / tomcat-embed-core >= 10.1.0-M1, < 10.1.14
Maven icon org.apache.tomcat.embed / tomcat-embed-core >= 9.0.0-M1, < 9.0.81
Maven icon org.apache.tomcat.embed / tomcat-embed-core >= 8.5.0, < 8.5.94
Maven icon org.apache.tomcat / tomcat-coyote >= 11.0.0-M1, < 11.0.0-M12
Maven icon org.apache.tomcat / tomcat-coyote >= 10.1.0-M1, < 10.1.14
Maven icon org.apache.tomcat / tomcat-coyote >= 9.0.0-M1, < 9.0.81
Maven icon org.apache.tomcat / tomcat-coyote >= 8.5.0, < 8.5.94
apache / tomcat = 9.0.0-milestone1
apache / tomcat = 9.0.0-milestone10
apache / tomcat = 9.0.0-milestone11
apache / tomcat = 9.0.0-milestone12
apache / tomcat = 9.0.0-milestone13
apache / tomcat = 9.0.0-milestone14
apache / tomcat = 9.0.0-milestone15
apache / tomcat = 9.0.0-milestone16
apache / tomcat = 9.0.0-milestone17
apache / tomcat = 9.0.0-milestone18
apache / tomcat = 9.0.0-milestone19
apache / tomcat = 9.0.0-milestone2
apache / tomcat = 9.0.0-milestone20
apache / tomcat = 9.0.0-milestone21
apache / tomcat = 9.0.0-milestone22
apache / tomcat = 9.0.0-milestone23
apache / tomcat = 9.0.0-milestone24
apache / tomcat = 9.0.0-milestone25
apache / tomcat = 9.0.0-milestone26
apache / tomcat = 9.0.0-milestone27
apache / tomcat = 9.0.0-milestone3
apache / tomcat = 9.0.0-milestone4
apache / tomcat = 9.0.0-milestone5
apache / tomcat = 9.0.0-milestone6
apache / tomcat = 9.0.0-milestone7
apache / tomcat = 9.0.0-milestone8
apache / tomcat = 9.0.0-milestone9
apache / tomcat = 10.1.0-milestone1
apache / tomcat = 10.1.0-milestone10
apache / tomcat = 10.1.0-milestone11
apache / tomcat = 10.1.0-milestone12
apache / tomcat = 10.1.0-milestone13
apache / tomcat = 10.1.0-milestone14
apache / tomcat = 10.1.0-milestone15
apache / tomcat = 10.1.0-milestone16
apache / tomcat = 10.1.0-milestone17
apache / tomcat = 10.1.0-milestone18
apache / tomcat = 10.1.0-milestone19
apache / tomcat = 10.1.0-milestone2
apache / tomcat = 10.1.0-milestone20
apache / tomcat = 10.1.0-milestone3
apache / tomcat = 10.1.0-milestone4
apache / tomcat = 10.1.0-milestone5
apache / tomcat = 10.1.0-milestone6
apache / tomcat = 10.1.0-milestone7
apache / tomcat = 10.1.0-milestone8
apache / tomcat = 10.1.0-milestone9
apache / tomcat = 11.0.0-milestone1
apache / tomcat = 11.0.0-milestone10
apache / tomcat = 11.0.0-milestone11
apache / tomcat = 11.0.0-milestone2
apache / tomcat = 11.0.0-milestone3
apache / tomcat = 11.0.0-milestone4
apache / tomcat = 11.0.0-milestone5
apache / tomcat = 11.0.0-milestone6
apache / tomcat = 11.0.0-milestone7
apache / tomcat = 11.0.0-milestone8
apache / tomcat = 11.0.0-milestone9
debian / debian_linux = 10.0
debian / debian_linux = 11.0
debian / debian_linux = 12.0

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.