Vulnerability Database

328,409

Total vulnerabilities in the database

CVE-2021-25122

When responding to new h2c connection requests, Apache Tomcat versions 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41 and 8.5.0 to 8.5.61 could duplicate request headers and a limited amount of request body from one request to another meaning user A and user B could both see the results of user A's request.

CVSS v3:

  • Severity: High
  • Score: 7.5
  • AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v2:

  • Severity: Medium
  • Score: 5
  • AV:N/AC:L/Au:N/C:P/I:N/A:N

CWEs:

Software From Fixed in
apache / tomcat 9.0.0-milestone1 9.0.0-milestone1.x
apache / tomcat 9.0.0-milestone10 9.0.0-milestone10.x
apache / tomcat 9.0.0-milestone11 9.0.0-milestone11.x
apache / tomcat 9.0.0-milestone12 9.0.0-milestone12.x
apache / tomcat 9.0.0-milestone13 9.0.0-milestone13.x
apache / tomcat 9.0.0-milestone14 9.0.0-milestone14.x
apache / tomcat 9.0.0-milestone15 9.0.0-milestone15.x
apache / tomcat 9.0.0-milestone16 9.0.0-milestone16.x
apache / tomcat 9.0.0-milestone17 9.0.0-milestone17.x
apache / tomcat 9.0.0-milestone18 9.0.0-milestone18.x
apache / tomcat 9.0.0-milestone19 9.0.0-milestone19.x
apache / tomcat 9.0.0-milestone2 9.0.0-milestone2.x
apache / tomcat 9.0.0-milestone20 9.0.0-milestone20.x
apache / tomcat 9.0.0-milestone21 9.0.0-milestone21.x
apache / tomcat 9.0.0-milestone22 9.0.0-milestone22.x
apache / tomcat 9.0.0-milestone23 9.0.0-milestone23.x
apache / tomcat 9.0.0-milestone24 9.0.0-milestone24.x
apache / tomcat 9.0.0-milestone25 9.0.0-milestone25.x
apache / tomcat 9.0.0-milestone26 9.0.0-milestone26.x
apache / tomcat 9.0.0-milestone27 9.0.0-milestone27.x
apache / tomcat 9.0.0-milestone3 9.0.0-milestone3.x
apache / tomcat 9.0.0-milestone4 9.0.0-milestone4.x
apache / tomcat 9.0.0-milestone5 9.0.0-milestone5.x
apache / tomcat 10.0.0-milestone3 10.0.0-milestone3.x
apache / tomcat 10.0.0-milestone4 10.0.0-milestone4.x
apache / tomcat 10.0.0-milestone2 10.0.0-milestone2.x
apache / tomcat 10.0.0-milestone1 10.0.0-milestone1.x
apache / tomcat 10.0.0-milestone5 10.0.0-milestone5.x
apache / tomcat 10.0.0-milestone6 10.0.0-milestone6.x
apache / tomcat 10.0.0-milestone7 10.0.0-milestone7.x
apache / tomcat 10.0.0-milestone8 10.0.0-milestone8.x
apache / tomcat 10.0.0-milestone9 10.0.0-milestone9.x
apache / tomcat 9.0.0 9.0.41.x
apache / tomcat 8.5.0 8.5.61.x
apache / tomcat 10.0.0-milestone10 10.0.0-milestone10.x
apache / tomcat 10.0.0 10.0.0.x
debian / debian_linux 9.0 9.0.x
debian / debian_linux 10.0 10.0.x
oracle / managed_file_transfer 12.2.1.3.0 12.2.1.3.0.x
oracle / instantis_enterprisetrack 17.1 17.1.x
oracle / instantis_enterprisetrack 17.2 17.2.x
oracle / instantis_enterprisetrack 17.3 17.3.x
oracle / agile_plm 9.3.3 9.3.3.x
oracle / agile_plm 9.3.6 9.3.6.x
oracle / database 12.2.0.1 12.2.0.1.x
oracle / database 19c 19c.x
oracle / managed_file_transfer 12.2.1.4.0 12.2.1.4.0.x
oracle / siebel_ui_framework - 21.9.x
oracle / mysql_enterprise_monitor - 8.0.23.x
oracle / graph_server_and_client - 21.3.0
oracle / graph_server_and_client 21.3.0 21.3.0.x
oracle / database 21c 21c.x
oracle / communications_cloud_native_core_policy 1.14.0 1.14.0.x
oracle / communications_instant_messaging_server 10.0.1.5.0 10.0.1.5.0.x
oracle / communications_cloud_native_core_security_edge_protection_proxy 1.6.0 1.6.0.x
Maven icon org.apache.tomcat.embed / tomcat-embed-core 10.0.0 10.0.2
Maven icon org.apache.tomcat.embed / tomcat-embed-core 9.0.0 9.0.43
Maven icon org.apache.tomcat.embed / tomcat-embed-core 8.5.0 8.5.63

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.