GHSA-ppxx-5m9h-6vxf
MEDIUMquic-go's path validation mechanism can be exploited to cause denial of service
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
github.com/quic-go/quic-go🐹github.com/quic-go/quic-go🐹github.com/quic-go/quic-go🐹github.com/quic-go/quic-goReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/quic-go/quic-go | ≥ 0.40.0&&< 0.40.1 | 0.40.1 |
| 🐹Go | github.com/quic-go/quic-go | ≥ 0.39.0&&< 0.39.4 | 0.39.4 |
| 🐹Go | github.com/quic-go/quic-go | ≥ 0.38.0&&< 0.38.2 | 0.38.2 |
| 🐹Go | github.com/quic-go/quic-go | all versions | 0.37.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/quic-go/quic-go. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/quic-go/quic-go to 0.40.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-ppxx-5m9h-6vxf is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-ppxx-5m9h-6vxf is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-ppxx-5m9h-6vxf. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-ppxx-5m9h-6vxf in your dependencies?
O3 detects GHSA-ppxx-5m9h-6vxf across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.