CVE-2022-46149: Possible out-of-bounds read related to list-of-pointers

David Renshaw, the author of the Rust implementation of Cap'n Proto, discovered a security vulnerability affecting both the C++ and Rust implementations of Cap'n Proto. The vulnerability was discovered using fuzzing. In theory, the vulnerability could lead to out-of-bounds reads which could cause crashes or perhaps exfiltration of memory.

The vulnerability is exploitable only if an application performs a certain unusual set of actions. As of this writing, we are not aware of any applications that are actually affected. However, out of an abundance of caution, we are issuing a security advisory and advising everyone to patch.

Our security advisory explains the impact of the bug, what an app must do to be affected, and where to find the fix.

Check out David's blog post for an in-depth explanation of the bug itself, including some of the inner workings of Cap'n Proto.