Impact
An attacker is able allocate arbitrarily many bytes in the Bitswap server by sending many WANT_BLOCK and or WANT_HAVE requests which are queued in an unbounded queue, with allocations that persist even if the connection is closed.
This affects users accepting or connecting untrusted connections such as by running in the public swarm and no pnet config.
Nodes that are not publicly reachable but connects to untrusted nodes are also vulnerable to the untrusted nodes being connected to since libp2p connections are blindly bidirectional.
Patches
Workarounds
Use PNET, swarm filters or resource manager allows list to block untrusted connections.
Note that using the resource manager will disrupt both client and server features because the bitswap protocol is a message based protocol mixing requests and responses.
References
Impact
An attacker is able allocate arbitrarily many bytes in the Bitswap server by sending many
WANT_BLOCKand orWANT_HAVErequests which are queued in an unbounded queue, with allocations that persist even if the connection is closed.This affects users accepting or connecting untrusted connections such as by running in the public swarm and no pnet config.
Nodes that are not publicly reachable but connects to untrusted nodes are also vulnerable to the untrusted nodes being connected to since libp2p connections are blindly bidirectional.
Patches
boxoupdate in KuboWorkarounds
Use PNET, swarm filters or resource manager allows list to block untrusted connections.
Note that using the resource manager will disrupt both client and server features because the bitswap protocol is a message based protocol mixing requests and responses.
References