Laravel Reverb provides a real-time WebSocket communication backend for Laravel applications. In versions 1.6.3 and below, Reverb passes data from the Redis channel directly into PHP’s unserialize() function without restricting which classes can be instantiated, which leaves users vulnerable to Remote Code Execution. The exploitability of this vulnerability is increased because Redis servers are commonly deployed without authentication, but only affects Laravel Reverb when horizontal scaling is enabled (REVERB_SCALING_ENABLED=true). This issue has been fixed in version 1.7.0. As a workaround, require a strong password for Redis access and ensure the service is only accessible via a private network or local loopback, and/or set REVERB_SCALING_ENABLED=false to bypass the vulnerable logic entirely (if the environment uses only one Reverb node).
reverb
Vendor: laravel
Security Vulnerability Index
Page 1 / 1There exists a use after free vulnerability in Reverb. Reverb supports the VARIANT datatype, which is supposed to represent an arbitrary object in C++. When a tensor proto of type VARIANT is unpacked, memory is first allocated to store the entire tensor, and a ctor is called on each instance. Afterwards, Reverb copies the content in tensor_content to the previously mentioned pre-allocated memory, which results in the bytes in tensor_content overwriting the vtable pointers of all the objects which were previously allocated. Reverb exposes 2 relevant gRPC endpoints: InsertStream and SampleStream. The attacker can insert this stream into the server’s database, then when the client next calls SampleStream they will unpack the tensor into RAM, and when any method on that object is called (including its destructor) the attacker gains control of the Program Counter. We recommend upgrading past git commit https://github.com/google-deepmind/reverb/commit/6a0dcf4c9e842b7f999912f792aaa6f6bd261a25