GHSA-93j5-89vc-pph4
RabbitMQ Java client ValueReader: Unbounded recursive table/array nesting causes StackOverflowError DoS
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Maven | com.rabbitmq:amqp-client | < 5.33.1 | 5.33.1 |
Details
As written in the advisory (Markdown source, shown as plain text).
## Summary
`ValueReader.readTable()` and `readArray()` recursively call `readFieldValue()` with no depth limit. A malicious AMQP peer can crash the client JVM by sending a deeply nested table structure.
## Vulnerable Code
`src/main/java/com/rabbitmq/client/impl/ValueReader.java` lines 139-155 and 237-249:
```java
private static Map<String, Object> readTable(DataInputStream in) throws IOException {
long tableLength = unsignedExtend(in.readInt());
// ...
while(tableIn.available() > 0) {
String name = readShortstr(tableIn);
Object value = readFieldValue(tableIn); // recursive call
}
}
static Object readFieldValue(DataInputStream in) throws IOException {
switch(in.readUnsignedByte()) {
case 'F': value = readTable(in); // mutual recursion
case 'A': value = readArray(in); // mutual recursion
}
}
```
## Attack Scenario
A malicious AMQP server (or MitM) sends a `connection.start` frame with ~580 levels of nested tables. Each level costs ~7 bytes (4-byte length + 1-byte key length + 1-byte key + 1-byte type tag), totaling ~4060 bytes within the 131,072 byte max frame size. With the default JVM stack (~512KB, ~864 bytes/frame), this triggers `StackOverflowError`, killing the I/O thread.
Exploitable pre-authentication since `connection.start` is the very first server frame.
## Impact
Denial of service. `StackOverflowError` kills the client I/O thread.
## CWE
CWE-674: Uncontrolled Recursion
## Remediation
Add a depth counter to `readTable`/`readArray`/`readFieldValue` and throw `MalformedFrameException` when exceeding a threshold (e.g., 32).
References
External links from the advisory. They lead to third-party sites.
- https://github.com/rabbitmq/rabbitmq-java-client/security/advisories/GHSA-93j5-89vc-pph4
- https://github.com/rabbitmq/rabbitmq-java-client/pull/2007
- https://github.com/rabbitmq/rabbitmq-java-client/pull/2008
- https://github.com/rabbitmq/rabbitmq-java-client/commit/09af76fce136f3136931654a0a1d43095c80e2f0
- https://github.com/rabbitmq/rabbitmq-java-client/commit/db89e34809fbc6ba4e946615f297f3684ccd0acc
- https://github.com/rabbitmq/rabbitmq-java-client
- https://github.com/rabbitmq/rabbitmq-java-client/releases/tag/v5.33.1