GHSA-273h-gvwr-c3qj
GHSA-273h-gvwr-c3qj is a CWE-409 vulnerability in github.com/crowdsecurity/crowdsec. O3 Security confirms whether GHSA-273h-gvwr-c3qj is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
CrowdSec LAPI: Denial of Service via Unbounded Gzip Decompression
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-273h-gvwr-c3qj.
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.
Real-World Exposure
github.com/crowdsecurity/crowdsecReal-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
The LAPI router uses gin-contrib/gzip with DefaultDecompressHandle globally (pkg/apiserver/controllers/controller.go).
This middleware decompresses incoming request bodies without enforcing a maximum decompressed size.
The endpoints /v1/watchers or /v1/watchers/login require no authentication.
An attacker can send small gzip-compressed JSON payloads that, when decompressed, result in hundreds of MB of valid JSON occupying server memory.
Sending enough requests concurrently will cause LAPI to allocate excessive heap memory, leading the OS to forcibly terminate the process.
This vulnerability is not exploitable from the network in default configurations, as LAPI only listens on the loopback interface. If developers' applications are using a multi-server setup, LAPI will be exposed in the network, in which case they are at risk if untrusted IPs can access it.
Impact
Exploiting this vulnerability will make LAPI unreachable, meaning that bouncers will not be able to fetch new decisions (but existing decisions will still be enforced) and log processors will not be able to send alerts, effectively denying the creation of new decisions.
Workarounds
If the LAPI is exposed on the network (either directly or through a reverse proxy), for example in the case of a multi-server deployment, restrict access to trusted IP addresses.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/crowdsecurity/crowdsec | ≥ 1.7.0&&< 1.7.8 | 1.7.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/crowdsecurity/crowdsec. 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/crowdsecurity/crowdsec to 1.7.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-273h-gvwr-c3qj 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-273h-gvwr-c3qj 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-273h-gvwr-c3qj. 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-273h-gvwr-c3qj in your dependencies?
O3 detects GHSA-273h-gvwr-c3qj across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.