GHSA-5fm9-h728-fwpj
trust-dns vulnerable to Remote Attackers causing Denial-of-Service (packet loops) with crafted DNS packets
Blast Radius
trust-dns-server🦀trust-dns-serverReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
trust-dns and trust-dns-server are vulnerable to remotely triggered denial-of-service attacks, consuming both network and CPU resources.
DNS messages with the QR=1 bit set are responded to with a FormErr response.
This allows creating a traffic loop, in which these FormErr responses are sent nonstop between vulnerable servers.
There are two scenarios how this can be exploited: 1) Create a loop between two instances of trust-dns, consuming network resources, or 2) consuming the CPU of a single instance.
With two instances A and B an attacker sends a DNS query with a spoofed source IP address to A.
A replies with a FormErr to B.
Now both servers with ping-pong the message back and forth until by chance the packet is dropped in the network.
Multiple spoofed packets can be sent by the attacker, increasing resource consumption.
A single server can get locked up replying to itself. Same setup as above, but now A sends the reply to itself. The packet is sent out as fast as the CPU and network stack manage. This locks up a CPU core. Multiple packets from the attacker consume multiple CPU cores.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | trust-dns-server | all versions | 0.22.1 |
| 🦀crates.io | trust-dns-server | ≥ 0.23.0-alpha.2&&< 0.23.0-alpha.3 | 0.23.0-alpha.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for trust-dns-server. 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 trust-dns-server to 0.22.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5fm9-h728-fwpj 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-5fm9-h728-fwpj 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-5fm9-h728-fwpj. 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-5fm9-h728-fwpj in your dependencies?
O3 detects GHSA-5fm9-h728-fwpj across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.