Impact
The frame format in draft versions of the WebSocket protocol includes a length header that allows an arbitrarily large integer to be encoded as a sequence of bytes with the high bit set. By sending an indefinite sequence of bytes with values 0x80 or above, a client can make the server parse these bytes into an ever-growing integer. Since JavaScript numbers are 64-bit floating point values, this number will eventually lose precision and lead to the subsequent payload being parsed incorrectly.
Patches
The issue has been patched in version 0.7.5 by rejecting the message if the length header exceeds the configured maximum message length. All users should upgrade to this version.
Workarounds
No known workarounds exist.
Acknowledgements
This issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.
Impact
The frame format in draft versions of the WebSocket protocol includes a length header that allows an arbitrarily large integer to be encoded as a sequence of bytes with the high bit set. By sending an indefinite sequence of bytes with values 0x80 or above, a server or client can make the other peer parse these bytes into an ever-growing integer. Since Ruby integers are arbitrary precision, this can be used to make a WebSocket connection consume an unbounded amount of memory and lead to the host process running out of memory.
Patches
The issue has been patched in version 0.8.1. All users should upgrade to this version.
Workarounds
No known workarounds exist.
Acknowledgements
This issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.
Impact
If this library is used to implement a WebSocket server on top of a TCP server (rather than an HTTP server or framework) using the WebSocket::Driver.server() method, or, if it is used to complement a WebSocket client, then a peer can make a single connection consume an unbounded amount of memory by sending an HTTP request or response with a never-ending list of headers. This can lead to the receiving process running out of memory.
Patches
The issue has been patched in version 0.8.1, by limiting the total size of HTTP request/response lines and headers accepted by the parser to 32 kB. All users should upgrade to this version.
Workarounds
No known workarounds exist.
Acknowledgements
This issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.