CVE-2021-21348 is a security vulnerability that affects the popular open-source software package manager npm. It was discovered in February 2021, and a patch was released shortly after. The vulnerability allows an attacker to execute arbitrary code on a user's system by tricking them into installing a malicious package. This could potentially lead to complete control of the victim's machine, data theft, and other harmful actions.
The vulnerability is caused by a flaw in the way npm handles scripts that are included in a package's metadata. Specifically, it allows an attacker to inject arbitrary commands into a package's "preinstall" script, which is executed before the package is installed on the user's system. By doing so, an attacker could execute arbitrary code with the privileges of the user running the install command.
In response to the discovery of the vulnerability, the npm maintainers quickly released a patch and advised all users to upgrade to a version of npm that includes the fix. Users should also be cautious when installing packages from untrusted sources and verify the integrity of any packages they download. While there have been no reports of this vulnerability being exploited in the wild, it is important for users to take steps to protect themselves and keep their systems secure.