Description (as reported)
There is a memory leak when using GzipHandler in jetty-12.0.30 that can cause off-heap OOMs. This can be used for DoS attacks so I'm reporting this as a vulnerability.
The leak is created by requests where the request is inflated (Content-Encoding: gzip) and the response is not deflated (no Accept-Encoding: gzip). In these conditions, a new inflator will be created by GzipRequest and never released back into GzipRequest.__inflaterPool because gzipRequest.destory() is not called.
In heap dumps one can see thousands of java.util.zip.Inflator objects, which use both Java heaps and native memory. Leaking native memory causes of off-heap OOMs.
Code path in GzipHandler.handle():
- Line 601:
GzipRequest is created when request inflation is needed.
- Lines 611-616: The callback is only wrapped in
GzipResponseAndCallback when both inflation and deflation are needed.
- Lines 619-625: If the handler accepts the request (returns true),
gzipRequest.destroy() is only called in the "request not accepted" path (returns false)
When deflation is needed, GzipResponseAndCallback (lines 102 and 116) properly calls gzipRequest.destroy() in its succeeded() and failed() methods. But this wrapper is only created when deflation is needed.
Possible fix:
The callback should be wrapped whenever a GzipRequest is created, not just when deflation is needed. This ensures gzipRequest.destroy() is always called when the request completes.
Impact
The leak causes the JVM to crash with OOME.
Patches
No patches yet.
Workarounds
Disable GzipHandler.
References
jetty/jetty.project#14260
https://gitlab.eclipse.org/security/cve-assignment/-/issues/79
References
glebashnik Reporter
bjorncs Reporter
Description (as reported)
There is a memory leak when using
GzipHandlerin jetty-12.0.30 that can cause off-heap OOMs. This can be used for DoS attacks so I'm reporting this as a vulnerability.The leak is created by requests where the request is inflated (
Content-Encoding: gzip) and the response is not deflated (noAccept-Encoding: gzip). In these conditions, a new inflator will be created byGzipRequestand never released back intoGzipRequest.__inflaterPoolbecausegzipRequest.destory()is not called.In heap dumps one can see thousands of
java.util.zip.Inflatorobjects, which use both Java heaps and native memory. Leaking native memory causes of off-heap OOMs.Code path in
GzipHandler.handle():GzipRequestis created when request inflation is needed.GzipResponseAndCallbackwhen both inflation and deflation are needed.gzipRequest.destroy()is only called in the "request not accepted" path (returns false)When deflation is needed,
GzipResponseAndCallback(lines 102 and 116) properly callsgzipRequest.destroy()in itssucceeded()andfailed()methods. But this wrapper is only created when deflation is needed.Possible fix:
The callback should be wrapped whenever a
GzipRequestis created, not just when deflation is needed. This ensuresgzipRequest.destroy()is always called when the request completes.Impact
The leak causes the JVM to crash with OOME.
Patches
No patches yet.
Workarounds
Disable
GzipHandler.References
jetty/jetty.project#14260
https://gitlab.eclipse.org/security/cve-assignment/-/issues/79
References