GHSA-ppxx-5m9h-6vxf quic-go's path validation mechanism can be exploited to cause denial of service

• Go github.com/quic-go/quic-go: >= 0.40.0, < 0.40.1 → fixed in 0.40.1 • Go github.com/quic-go/quic-go: >= 0.39.0, < 0.39.4 → fixed in 0.39.4 • Go github.com/quic-go/quic-go: >= 0.38.0, < 0.38.2 → fixed in 0.38.2 • Go github.com/quic-go/quic-go: < 0.37.7 → fixed in 0.37.7

An attacker can cause its peer to run out of memory sending a large number of PATH_CHALLENGE frames. The receiver is supposed to respond to each PATH_CHALLENGE frame with a PATH_RESPONSE frame. The attacker can prevent the receiver from sending out (the vast majority of) these PATH_RESPONSE frames by collapsing the peers congestion window (by selectively acknowledging received packets) and by manipulating the peer's RTT estimate. I published a more detailed description of the attack and its mitigation in this blog post: https://seemann.io/posts/2023-12-18-exploiting-quics-path-validation/ There's no way to mitigate this attack, please update quic-go to a version that contains the fix.