Severity: medium (4.3)
First published: Fri Sep 15 2023
Last modified: Wed Sep 20 2023
CWE: 1390
Jetty is a Java based web server and servlet engine. Versions 9.4.21 through 9.4.51, 10.0.15, and 11.0.15 are vulnerable to weak authentication. If a Jetty `OpenIdAuthenticator` uses the optional nested `LoginService`, and that `LoginService` decides to revoke an already authenticated user, then the current request will still treat the user as authenticated. The authentication is then cleared from the session and subsequent requests will not be treated as authenticated. So a request on a previously authenticated session could be allowed to bypass authentication after it had been rejected by the `LoginService`. This impacts usages of the jetty-openid which have configured a nested `LoginService` and where that `LoginService` will is capable of rejecting previously authenticated users. Versions 9.4.52, 10.0.16, and 11.0.16 have a patch for this issue.
If a Jetty `OpenIdAuthenticator` uses the optional nested `LoginService`, and that `LoginService` decides to revoke an already authenticated user, then the current request will still treat the user as authenticated. The authentication is then cleared from the session and subsequent requests will not be treated as authenticated. So a request on a previously authenticated session could be allowed to bypass authentication after it had been rejected by the `LoginService`. ### Impact This impacts usages of the jetty-openid which have configured a nested `LoginService` and where that `LoginService` will is capable of rejecting previously authenticated users. ### Original Report > working on a custom OpenIdAuthenticator, I discovered the following: > > https://github.com/eclipse/jetty.project/blob/jetty-10.0.14/jetty-openid/src/main/java/org/eclipse/jetty/security/openid/OpenIdAuthenticator.java#L505 > > In the case where the LoginService does return that the authentication has been revoked (from the validate() call on line 463), the OpenIdAuthenticator removes the authentication from the session; however the current request still proceeds as if authenticated, since it falls through to "return authentication" on line 505. > > This is fixed by moving the line 505 (and associated debug log) inside the else block that ends on line 502, instead of outside it. Then the revocation case will run through to line 517 and will trigger a new OpenId authentication which I think is correct. > > I think this revocation can only occur if you do attach a separate LoginService to the OpenIdLoginService, but in that case the revoked authentication will still let the next request through (and possibly more than one if they are very close to simultaneous). > > Technically I think this is a security vulnerability, if a very minor one, so I'm sending this off-list. ### Patched Versions Fixed in Jetty Versions: * 9.4.52 - fixed in PR https://github.com/eclipse/jetty.project/pull/9660 * 10.0.16 - fixed in PR https://github.com/eclipse/jetty.project/pull/9528 * 11.0.16 - fixed in PR https://github.com/eclipse/jetty.project/pull/9528 * 12.0.0 - not impacted (already has fix) ### Workaround Upgrade your version of Jetty. ### References * https://github.com/eclipse/jetty.project/pull/9528 * https://github.com/eclipse/jetty.project/pull/9660
CVE-2023-41900 is a vulnerability in Jetty, a Java-based web server and servlet engine, which allows an authenticated user to have their authentication cleared from the session.
CVE-2023-41900 has a severity rating of 4.3, which is considered medium.
Jetty versions 9.4.21 through 9.4.51, 10.0.15, and 11.0.0 through 11.0.15 are affected by CVE-2023-41900.
To fix CVE-2023-41900, you should update Jetty to version 9.4.52, 10.0.16, or 11.0.16, depending on your current version.
Yes, you can find references for CVE-2023-41900 at the following links: [URL1], [URL2], [URL3].
