CVE-2020-19676 — nacos-common
MEDIUMCVE-2020-19676 is a medium-severity (CVSS 5.3) vulnerability in com.alibaba.nacos:nacos-common. 1 public exploit reference exists, so weaponization risk is real. A fix is available for com.alibaba.nacos:nacos-common — see the affected versions and patch details below.
Incorrect Access Control in Nacos
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-19676 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
com.alibaba.nacos:nacos-commonReal-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
Nacos 1.1.4 is affected by: Incorrect Access Control. An environment can be set up locally to get the service details interface. Then other Nacos service names can be accessed through the service list interface. Service details can then be accessed when not logged in. (detail:https://github.com/alibaba/nacos/issues/2284)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.alibaba.nacos:nacos-common | all versions | 1.2.0com.alibaba.nacos:nacos-common:1.2.0 |
Affected Products
nacosalibabaResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.alibaba.nacos:nacos-common, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.alibaba.nacos:nacos-common to 1.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-19676 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2020-19676 in your dependencies?
Find it across Maven, including transitive dependencies.