CVE-2021-28169
Jetty Utility Servlets ConcatServlet Double Decoding Information Disclosure Vulnerability
Impact
Requests to the `ConcatServlet` and `WelcomeFilter` are able to access protected resources within the `WEB-INF` directory. For example a request to the `ConcatServlet` with a URI of `/concat?/%2557EB-INF/web.xml` can retrieve the web.xml file. This can reveal sensitive information regarding the implementation of a web application. This occurs because both `ConcatServlet` and `WelcomeFilter` decode the supplied path to verify it is not within the `WEB-INF` or `META-INF` directories. It then uses this decoded path to call `RequestDispatcher` which will also do decoding of the path. This double decoding allows paths with a doubly encoded `WEB-INF` to bypass this security check. ### Impact This affects all versions of `ConcatServlet` and `WelcomeFilter` in versions before 9.4.41, 10.0.3 and 11.0.3. ### Workarounds If you cannot update to the latest version of Jetty, you can instead deploy your own version of the [`ConcatServlet`](https://github.com/eclipse/jetty.project/blob/4204526d2fdad355e233f6bf18a44bfe028ee00b/jetty-servlets/src/main/java/org/eclipse/jetty/servlets/ConcatServlet.java) and/or the [`WelcomeFilter`](https://github.com/eclipse/jetty.project/blob/4204526d2fdad355e233f6bf18a44bfe028ee00b/jetty-servlets/src/main/java/org/eclipse/jetty/servlets/WelcomeFilter.java) by using the code from the latest version of Jetty.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| maven | org.eclipse.jetty:jetty-servlets | <= 9.4.40 | 9.4.41 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Eclipse | Jetty | before 9.4.41 from 10.0.0 before 10.0.3 from 11.0.0 before 11.0.3 |
| Debian | Debian Linux | Versions 9.0, 10.0 |
| Oracle | Communications Cloud Native Core Policy | Version 1.14.0 |
| Oracle | Rest Data Services | before 21.3 |
| Netapp | Active Iq Unified Manager | All versions |
| Netapp | Hci | All versions |
| Netapp | Management Services For Element Software | All versions |
| Netapp | Snap Creator Framework | All versions |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/eclipse/jetty.project/security/advisories/GHSA-gwcr-j4wh-j3cq
- https://lists.apache.org/thread.html/r04a4b4553a23aff26f42635a6ae388c3b162aab30a88d12e59d05168%40%3Cjira.kafka.apache.org%3E
- https://lists.apache.org/thread.html/r234f6452297065636356f43654cdacef565b8f9ceb0e0c07ffb8c73b%40%3Cdev.kafka.apache.org%3E
- https://lists.apache.org/thread.html/r2721aba31a8562639c4b937150897e24f78f747cdbda8641c0f659fe%40%3Cusers.kafka.apache.org%3E
- https://lists.apache.org/thread.html/r284de9c5399486dfff12ab9e7323ca720dd7019a9a3e11c8510a7140%40%3Cjira.kafka.apache.org%3E
- https://lists.apache.org/thread.html/r29678972c3f8164b151fd7a5802785d402e530c09870a82ffc7681a4%40%3Cdev.kafka.apache.org%3E
- https://lists.apache.org/thread.html/r32b0b640ad2be3b858f0af51c68a7d5c5a66a462c8bbb93699825cd3%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r33eb06b05afbc7df28d31055cae0cb3fd36cab808c884bf6d680bea5%40%3Cdev.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r67c4f90658fde875521c949448c54c98517beecdc7f618f902c620ec%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r8a1a332899a1f92c8118b0895b144b27a78e3f25b9d58a34dd5eb084%40%3Cnotifications.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r91e34ff61aff8fd25a3f2a21539597c6ef7589a31c199b0a9546477c%40%3Cjira.kafka.apache.org%3E
- https://lists.apache.org/thread.html/rb1292d30462b9baedea7c5d9594fc75990d9aa0ec223b48054ca9c25%40%3Cjira.kafka.apache.org%3E
- https://lists.apache.org/thread.html/rbefa055282d52d6b58d29a79fbb0be65ab0a38d25f00bd29eaf5e6fd%40%3Cnotifications.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/rd5b52362f5edf98e0dcab6541a381f571cccc05ad9188e793af688f3%40%3Cjira.kafka.apache.org%3E
- https://lists.apache.org/thread.html/rddbb4f8d5db23265bb63d14ef4b3723b438abc1589f877db11d35450%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/ref1c161a1621504e673f9197b49e6efe5a33ce3f0e6d8f1f804fc695%40%3Cjira.kafka.apache.org%3E
- https://lists.apache.org/thread.html/rf36f1114e84a3379b20587063686148e2d5a39abc0b8a66ff2a9087a%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/rfff6ff8ffb31e8a32619c79774def44b6ffbb037c128c5ad3eab7171%40%3Cissues.zookeeper.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2021/06/msg00017.html
- https://security.netapp.com/advisory/ntap-20210727-0009/
- https://www.debian.org/security/2021/dsa-4949
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://github.com/advisories/GHSA-gwcr-j4wh-j3cq