CVE-2023-45648
Published: 10 October 2023
Summary
CVE-2023-45648 is a medium-severity Improper Input Validation (CWE-20) vulnerability in Apache Tomcat. Its CVSS base score is 5.3 (Medium).
Operationally, ranked in the top 1.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
Apache Tomcat contains an improper input validation flaw that affects versions 11.0.0-M1 through 11.0.0-M11, 10.1.0-M1 through 10.1.13, 9.0.0-M1 through 9.0.81, and 8.5.0 through 8.5.93, with older end-of-life releases also potentially impacted. The server fails to correctly parse HTTP trailer headers, allowing a specially crafted invalid trailer to cause a single request to be interpreted as multiple requests.
An unauthenticated remote attacker can supply the malformed trailer when Tomcat sits behind a reverse proxy, enabling HTTP request smuggling that may result in partial integrity impact such as request manipulation or cache poisoning. The vulnerability carries a CVSS 3.1 score of 5.3 reflecting network attack vector, low complexity, and no required privileges or user interaction.
Apache Tomcat project advisories and downstream distributions including Debian LTS and NetApp recommend upgrading to fixed releases 11.0.0-M12, 10.1.14, 9.0.82, or 8.5.94 and later. The associated EPSS score has remained near 0.62 with a modest peak of 0.66 and shows no material post-disclosure rise that would indicate emerging exploitation interest.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-2799
Vulnerability details
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…
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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.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.
Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.
Directly implements checks on information inputs to reject invalid data before processing.
Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.