Node Version Manager (nvm) is a POSIX-compliant shell function for managing multiple node.js versions. In versions 0.31.2 through 0.40.5, `nvm_ls` filters installed versions with a sed program that embeds the requested version pattern in a `\\#...#` address, escaping `.` (and, since 0.40.4, `#`) but not backslash. A version string containing `#` (or `\\#`) therefore closes the address early, and the rest of it is parsed as sed commands: with GNU sed, the `e` command runs a shell command as the user; with BSD sed, the `w` and `r` commands write and read files. This is reachable whenever an attacker-influenced version string is passed to `nvm use`, `nvm which`, `nvm ls`, `nvm version`, `nvm run`, or `nvm exec`, or to `nvm-exec` via `NODE_VERSION`, and at least one version is installed. nvm's own `.nvmrc` parser strips comments, so a bare `nvm use` is not affected; however, the bash `cdnvm` and zsh `load-nvmrc` auto-switch hooks documented in the README read `.nvmrc` as-is and pass it to `nvm ls` and `nvm version`, so a user with one of those hooks installed runs the attacker's command just by changing into a directory under a malicious `.nvmrc`; scripts that run `nvm use \"$(cat .nvmrc)\"` are affected the same way. Version 0.40.6 passes any version pattern containing `#` or a newline through the `.nvmrc` content parser first, so no `#` reaches the sed program.
"}]}],"references":[{"url":"https://github.com/nvm-sh/nvm/security/advisories/GHSA-vgqf-vc3m-4wv3","name":"GHSA-vgqf-vc3m-4wv3","tags":["vendor-advisory"]},{"url":"https://github.com/nvm-sh/nvm/commit/82315e2b189528a006da6701eac30e8c364ffd22","name":"Fix commit 82315e2b","tags":["patch"]},{"url":"https://github.com/nvm-sh/nvm/pull/3854","name":"nvm-sh/nvm#3854","tags":["patch"]},{"url":"https://github.com/nvm-sh/nvm/releases/tag/v0.40.6","name":"v0.40.6","tags":["release-notes"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"ACTIVE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":7.1,"vectorString":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseSeverity":"HIGH","baseScore":7,"vectorString":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"}}],"workarounds":[{"lang":"en","value":"Until upgrading, do not pass untrusted version strings to nvm, and use nvm's own `.nvmrc` handling (a bare `nvm use`) instead of reading `.nvmrc` yourself, including in shell auto-switch hooks.","supportingMedia":[{"type":"text/html","base64":false,"value":"Until upgrading, do not pass untrusted version strings to nvm, and use nvm's own `.nvmrc` handling (a bare `nvm use`) instead of reading `.nvmrc` yourself, including in shell auto-switch hooks.
"}]}],"solutions":[{"lang":"en","value":"Upgrade to nvm 0.40.6 or later.","supportingMedia":[{"type":"text/html","base64":false,"value":"Upgrade to nvm 0.40.6 or later.
"}]}],"credits":[{"lang":"en","value":"vnth4nhnt of CyStack (https://github.com/vnth4nhnt)","type":"finder"},{"lang":"en","value":"sjh9714 (https://github.com/sjh9714)","type":"remediation developer"}],"source":{"advisory":"GHSA-vgqf-vc3m-4wv3","discovery":"EXTERNAL"}}}}