VDB
KO
HIGH 7.5

GHSA-v74w-7mr3-4qg3

Netty: Denial of Service in XmlFrameDecoder via CPU Exhaustion

Quick fix

GHSA-v74w-7mr3-4qg3 — io.netty:netty-codec-xml: upgrade to the fixed version with the command below.

# pom.xml: bump <version>4.2.16.Final</version> for io.netty:netty-codec-xml

Details

### Summary An attacker can cause Denial of Service by sending a specially crafted malicious XML payload (e.g., repeated `</` characters) to a Netty server utilizing XmlFrameDecoder, causing the server's EventLoop thread to exhaust CPU resources and become unresponsive.

### Details `io.netty.handler.codec.xml.XmlFrameDecoder` suffers from a vulnerability resulting in CPU exhaustion. When `<` followed by `/` is encountered, the decoder scans the remaining buffer for a closing `>`. Because the parser state is not saved between `decode()` invocations, an attacker can trickle-feed a payload of `</` characters. This forces the decoder to repeatedly rescan the entire accumulated buffer. A 1MB `maxFrameLength` is enough to completely hang a server's thread while it loops endlessly.

### Impact Denial of Service via CPU Exhaustion. Any application utilizing Netty's XmlFrameDecoder is impacted. An unauthenticated remote attacker can exploit this flaw by sending a modest amount of malformed XML data to an exposed port.

Are you affected?

Enter the version of the package you're using.

Affected packages

Maven / io.netty:netty-codec-xml
Introduced in: 4.2.0.Final Fixed in: 4.2.16.Final
Fix # pom.xml: bump <version>4.2.16.Final</version> for io.netty:netty-codec-xml
Maven / io.netty:netty-codec-xml
Introduced in: 0 Fixed in: 4.1.136.Final
Fix # pom.xml: bump <version>4.1.136.Final</version> for io.netty:netty-codec-xml

References