webtransport-go is an implementation of the WebTransport protocol. Prior to 0.11.1, Session.parseNextCapsule() in session.go skips an unknown WebTransport capsule on the HTTP/3 request stream by calling io.ReadAll on the capsule reader, retaining the complete declared capsule body in memory. A malicious peer can send a large unknown capsule and cause a client or server to allocate memory for the full payload; QUIC flow control does not bound the total retained allocation because reading advances the flow-control window while the received bytes remain in memory.
The resulting memory and resource exhaustion can disrupt or crash the affected process. This issue is fixed in version 0.11.1.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
Low
Partial disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 4
https://github.com/quic-go/webtransport-go/commit/3aecd11736579530ff067651c30a5…
security-advisories@github.com
https://github.com/quic-go/webtransport-go/pull/290
security-advisories@github.com
https://github.com/quic-go/webtransport-go/releases/tag/v0.11.1
security-advisories@github.com
https://github.com/quic-go/webtransport-go/security/advisories/GHSA-g35j-m5xg-v…
security-advisories@github.com