CVE-2019-16869
HTTP Request Smuggling vulnerability in netty-all (Maven)
What is CVE-2019-16869 About?
This vulnerability is an HTTP Request Smuggling flaw in Netty, caused by improper handling of whitespace in HTTP headers. It could allow attackers to bypass security controls or access unauthorized content by manipulating how requests are parsed. Exploitation typically requires specific conditions but can be moderately complex to execute effectively.
Affected Software
Technical Details
The Netty framework, specifically versions before 4.1.42.Final, improperly processes HTTP headers containing whitespace before the colon, such as 'Transfer-Encoding : chunked'. This malformed header allows for discrepancies in how a proxy or load balancer interprets the request versus how the backend server (running Netty) interprets it. By sending a request with a 'Transfer-Encoding' header containing whitespace, an attacker can cause one system to see a single HTTP request while another sees two distinct requests, leading to request smuggling. This technique can bypass security devices, access internal services, or poison web caches.
What is the Impact of CVE-2019-16869?
Successful exploitation may allow attackers to bypass security mechanisms, access unauthorized resources, poison web caches, or perform other malicious actions that leverage the discrepancy in request parsing.
What is the Exploitability of CVE-2019-16869?
Exploitation of this vulnerability requires a good understanding of HTTP request smuggling techniques and the specific behavior of Netty in conjunction with front-end proxies or load balancers. There are no direct authentication or privilege requirements to initiate the attack, as it targets how the HTTP protocol is parsed. Access can be remote. The attacker needs to craft specially malformed HTTP requests that exploit the whitespace parsing flaw. The likelihood of successful exploitation increases if the affected Netty instance is deployed behind a proxy that interprets HTTP headers differently, creating an exploitable boundary.
What are the Known Public Exploits?
| PoC Author | Link | Commentary |
|---|---|---|
| No known exploits | ||
What are the Available Fixes for CVE-2019-16869?
Available Upgrade Options
- io.netty:netty-all
- >4.0.0.Alpha1, <4.1.42.Final → Upgrade to 4.1.42.Final
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Book a demoAdditional Resources
- https://lists.apache.org/thread.html/re45ee9256d3233c31d78e59ee59c7dc841c7fbd83d0769285b41e948@%3Ccommits.druid.apache.org%3E
- https://lists.apache.org/thread.html/r831e0548fad736a98140d0b3b7dc575af0c50faea0b266434ba813cc@%3Cdev.rocketmq.apache.org%3E
- https://lists.apache.org/thread.html/d3eb0dbea75ef5c400bd49dfa1901ad50be606cca3cb29e0d01b6a54%40%3Cissues.zookeeper.apache.org%3E
- https://seclists.org/bugtraq/2020/Jan/6
- https://lists.apache.org/thread.html/380f6d2730603a2cd6b0a8bea9bcb21a86c199147e77e448c5f7390b@%3Ccommits.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/rc8d554aad889d12b140d9fd7d2d6fc2e8716e9792f6f4e4b2cdc2d05%40%3Ccommits.cassandra.apache.org%3E
- https://lists.apache.org/thread.html/6e1e34c0d5635a987d595df9e532edac212307243bb1b49eead6d55b@%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/rd0e44e8ef71eeaaa3cf3d1b8b41eb25894372e2995ec908ce7624d26%40%3Ccommits.pulsar.apache.org%3E
- https://lists.apache.org/thread.html/rc8d554aad889d12b140d9fd7d2d6fc2e8716e9792f6f4e4b2cdc2d05@%3Ccommits.cassandra.apache.org%3E
- https://lists.apache.org/thread.html/raaac04b7567c554786132144bea3dcb72568edd410c1e6f0101742e7%40%3Cissues.flink.apache.org%3E
What are Similar Vulnerabilities to CVE-2019-16869?
Similar Vulnerabilities: CVE-2019-19901 , CVE-2019-19902 , CVE-2020-13101 , CVE-2021-23348
