rabbitmq-c is a C-language AMQP client library for RabbitMQ. Prior to version 0.17.0, the bounds check (*offset = o + len) <= encoded.len overflows when o + len > SIZE_MAX on 32-bit systems. len is a uint32_t read from the AMQP wire as a BYTES/UTF8 field length. The overflow wraps the check to a small value that passes, producing a decoded amqp_bytes_t with a multi-GB .len pointing into a small frame buffer. This results in an out-of-bounds read of up to ~4GB of process memory on 32-bit systems (ARM, MIPS, x86 ILP32, embedded IoT AMQP clients). Enabling information disclosure or denial of service. Not exploitable on 64-bit systems where size_t is 64-bit. This issue has been patched in version 0.17.0.
Weakness
The product reads data past the end, or before the beginning, of the intended buffer.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Librabbitmq | Ubuntu | esm-apps-legacy/xenial | * |
| Librabbitmq | Ubuntu | esm-apps/bionic | * |
| Librabbitmq | Ubuntu | esm-infra-legacy/trusty | * |
| Librabbitmq | Ubuntu | esm-infra/focal | * |
| Librabbitmq | Ubuntu | jammy | * |
| Librabbitmq | Ubuntu | noble | * |
| Librabbitmq | Ubuntu | resolute | * |
| Librabbitmq | Ubuntu | upstream | * |
Potential Mitigations
- Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
- When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
- Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
- To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.