CVE-2021-30181 — dubbo
CRITICALCVE-2021-30181 is a critical-severity (CVSS 9.8) remote code execution vulnerability in com.alibaba:dubbo. EPSS puts its 30-day exploitation probability at 60.6% (99th percentile). A fix is available for com.alibaba:dubbo — see the affected versions and patch details below.
Code injection in Apache Dubbo
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.
How urgent is this, really
CVE-2021-30181 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
com.alibaba:dubbo☕org.apache.dubbo:dubboReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Apache Dubbo prior to 2.6.9 and 2.7.9 supports Script routing which will enable a customer to route the request to the right server. These rules are used by the customers when making a request in order to find the right endpoint. When parsing these rules, Dubbo customers use ScriptEngine and run the rule provided by the script which by default may enable executing arbitrary code.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.alibaba:dubbo | ≥ 2.5.0&&< 2.6.9 | 2.6.9com.alibaba:dubbo:2.6.9 |
| ☕Maven | org.apache.dubbo:dubbo | ≥ 2.5.0&&< 2.7.10 | 2.7.10org.apache.dubbo:dubbo:2.7.10 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.alibaba:dubbo, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.alibaba:dubbo to 2.6.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-30181 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2021-30181 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2021-30181. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2021-30181 in your dependencies?
O3 Security finds CVE-2021-30181 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.