Node Version Manager (nvm) is a POSIX-compliant shell function for managing multiple node.js versions. In versions 0.32.1 through 0.40.5, `nvm ls-remote` (and other commands that refresh remote LTS aliases, such as `nvm install --lts`) parse the node.js mirror's `index.tab` and use each release's LTS codename field as an alias filename without validating it. A malicious, compromised, or man-in-the-middled mirror can return an LTS codename containing path-traversal sequences such as `../../../.bashrc`, causing nvm to write the associated version string to a path outside `$NVM_DIR/alias`. With the default layout (`$NVM_DIR` is `~/.nvm`), this can create or overwrite files in the user's home directory, including shell startup files, which can lead to code execution in a later shell session. Exploitation requires the victim to use a hostile mirror -- via a compromised mirror or CDN, a network man-in-the-middle, or a maliciously configured `NVM_NODEJS_ORG_MIRROR`/`NVM_IOJS_ORG_MIRROR` -- and to run an affected command. Version 0.40.6 validates remote LTS codenames as safe alias filenames and rejects `..` path components when writing alias files.

nvm (Node Version Manager) through 0.40.4 executes arbitrary commands from version strings supplied by the configured Node.js/io.js mirror. Commands such as `nvm install` read the available versions from the mirror's index.tab and use the selected version, without sanitization, to build download URLs and shell/awk commands. Two sinks are affected by the same untrusted input: nvm_download() built a curl/wget command string and ran it with `eval`, so a version field containing command substitution (for example $(id)) was executed by the local shell; and nvm_get_checksum() interpolated the version-derived download slug into an awk program, so a crafted version could execute arbitrary commands via awk's system(). An attacker who controls the configured mirror, supplies mirror content to a user or CI on a non-default mirror, or machine-in-the-middles a non-TLS mirror can ∴ run arbitrary commands with the privileges of the user running nvm. The default mirror (https://nodejs.org over TLS) is not affected. Fixed on master (pending the next tagged release) by passing every argument as a literal argv element instead of using eval, by passing the value to awk as data via -v instead of interpolating it into the program, and by rejecting any version outside the Node.js/io.js version grammar before it is used.

A command injection vulnerability exists in nvm (Node Version Manager) versions 0.40.3 and below. The nvm_download() function uses eval to execute wget commands, and the NVM_AUTH_HEADER environment variable was not sanitized in the wget code path (though it was sanitized in the curl code path). An attacker who can set environment variables in a victim's shell environment (e.g., via malicious CI/CD configurations, compromised dotfiles, or Docker images) can inject arbitrary shell commands that execute when the victim runs nvm commands that trigger downloads, such as 'nvm install' or 'nvm ls-remote'.