GHSA-c653-97m9-rcg9
Netty: Wrapping plain trust manager silently disables hostname verification
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Maven | io.netty:netty-handler | >= 4.2.0.Final, < 4.2.15.Final | 4.2.15.Final |
| Maven | io.netty:netty-handler | < 4.1.135.Final | 4.1.135.Final |
Details
As written in the advisory (Markdown source, shown as plain text).
SimpleTrustManagerFactory.engineGetTrustManagers() and related paths wrap any user-supplied plain X509TrustManager in X509TrustManagerWrapper, which extends X509ExtendedTrustManager but implements the 3-arg checkServerTrusted(chain, authType, SSLEngine) by discarding the SSLEngine and calling the 2-arg delegate. Because the object now IS an X509ExtendedTrustManager, neither SunJSSE's internal AbstractTrustManagerWrapper nor Netty's own OpenSslX509TrustManagerWrapper will re-wrap it to add endpoint-identification. Consequently, even though Netty 4.2 sets endpointIdentificationAlgorithm="HTTPS" by default, a client built with `SslContextBuilder.forClient().trustManager(somePlainX509TrustManager)` performs no hostname verification at all.
References
External links from the advisory. They lead to third-party sites.