Vulnerabilities are known reported security threats that affect a large amount of packages in the npm ecosystem. To mitigate these security threats, the open-source community strongly suggests vulnerable packages to timely publish vulnerability fixes and recommends affected packages to update their dependencies. However, there are still serious lags in the propagation of vulnerability fixes in the ecosystem. In our preliminary study on the latest versions of 356,283 active npm packages, we found that 20.0% of them can still introduce vulnerabilities via direct or transitive dependencies although the involved vulnerable packages have already published fix versions for over a year. Prior study by (Chinthanet et al. 2021) lays the groundwork for research on how to mitigate propagation lags of vulnerability fixes in an ecosystem. They conducted an empirical investigation to identify lags that might occur between the vulnerable package release and its fixing release. They found that factors such as the branch upon which a fix landed and the severity of the vulnerability had a small effect on its propagation trajectory throughout the ecosystem. To ensure quick adoption and propagation of a release that contains the fix, they gave several actionable advice to developers and researchers. However, it is still an open question how to design an effective technique to accelerate the propagation of vulnerability fixes. Motivated by this problem, in this paper, we conducted an empirical study to learn the scale of packages that block the propagation of vulnerability fixes in the ecosystem and investigate their evolution characteristics. Furthermore, we distilled the remediation strategies that have better effects on mitigating the fix propagation lags. Leveraging our empirical findings, we propose an ecosystem-level technique, Plumber, for deriving feasible remediation strategies to boost the propagation of vulnerability fixes. To precisely diagnose the causes of fix propagation ...