PT-2026-80233 · Maven · Com.Rabbitmq:Amqp-Client

Published

2026-08-18

·

Updated

2026-08-18

CVSS v4.0

8.7

High

VectorAV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Summary

ValueReader.readBytes() allocates a byte array sized by a wire-declared content length without validating it against actual frame data. A malicious AMQP peer triggers OOM by declaring a ~2GB string/bytes field.

Vulnerable Code

src/main/java/com/rabbitmq/client/impl/ValueReader.java lines 83-95:
java
private static byte[] readBytes(final DataInputStream in) throws IOException {
  final long contentLength = unsignedExtend(in.readInt());
  if(contentLength < Integer.MAX VALUE) {
    final byte[] buffer = new byte[(int)contentLength]; // allocates before reading
    in.readFully(buffer);
    return buffer;
  }
}

Attack Scenario

A malicious AMQP server sends a LongString field (type tag 'S') with declared length 0x7FFFFFFE (2,147,483,646). The check contentLength < Integer.MAX VALUE passes. new byte[2147483646] attempts ~2GB allocation, causing OutOfMemoryError before readFully() attempts to read data.
The allocation size is attacker-controlled and is NOT validated against the frame size or TruncatedInputStream bounds. Exploitable pre-authentication via connection.start server-properties table.

Impact

Denial of service via JVM OutOfMemoryError. Crashes the entire JVM.

CWE

CWE-789: Memory Allocation with Excessive Size Value

Remediation

Validate contentLength against the frame's remaining bytes or the negotiated max frame size (default 131,072) before allocating.

Fix

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Weakness Enumeration

Related Identifiers

GHSA-68MJ-5WR7-6FGG

Affected Products

Com.Rabbitmq:Amqp-Client