SRC-2021-0017 : Jetty Utility Servlets ConcatServlet Double Decoding Information Disclosure Vulnerability

CVE ID: CVE-2021-28169

CVSS Score: 5.3, (/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)

Affected Vendors: Jetty

Affected Products: org.eclipse.jetty:jetty-servlets

Vulnerability Details: This vulnerability allows remote attackers to disclose information on affected installations of Jetty Web Server. Authentication is not required to exploit this vulnerability. The specific flaw exists within the ConcatServlet and WelcomeFilter classes. The issue results from the lack of proper validation of a user-supplied path. An attacker can leverage this vulnerability to disclose sensitive files under the web root context.

Vendor Response:

Jetty has issued an update to correct this vulnerability. More details can be found at:

Disclosure Timeline:

  • 2021-05-05 – Sent to Eclipse maintainers

  • 2021-06-04 – Coordinated public release of advisory

Credit: This vulnerability was discovered by Steven Seeley (mr_me) of Qihoo 360 Vulcan Team