diff --git a/nvm.sh b/nvm.sh index e59cf3f2..486126c6 100755 --- a/nvm.sh +++ b/nvm.sh @@ -1927,7 +1927,7 @@ nvm_get_checksum() { SHASUMS_URL="${MIRROR}/${3}/SHASUMS.txt" fi - nvm_download -L -s "${SHASUMS_URL}" -o - | command awk "{ if (\"${4}.${5}\" == \$2) print \$1}" + nvm_download -L -s "${SHASUMS_URL}" -o - | command awk -v tarball="${4}.${5}" '{ if (tarball == $2) print $1 }' } nvm_print_versions() { diff --git a/test/fast/Unit tests/nvm_get_checksum awk injection b/test/fast/Unit tests/nvm_get_checksum awk injection new file mode 100755 index 00000000..63914e30 --- /dev/null +++ b/test/fast/Unit tests/nvm_get_checksum awk injection @@ -0,0 +1,28 @@ +#!/bin/sh + +WORK="${TMPDIR:-/tmp}/nvm_get_checksum_awk.$$" +PROOF="${WORK}/PWNED" + +cleanup () { + unset -f die cleanup nvm_download + rm -rf "${WORK}" +} +die () { echo "$@" ; cleanup ; exit 1; } + +\. ../../../nvm.sh + +mkdir -p "${WORK}" + +# GHSA-3c52-35h2-gfmm: nvm_get_checksum must treat the (untrusted, version-derived) +# slug as awk data, never as awk program text. +# given a crafted slug carrying an unconditional awk system() action +# and a mock that supplies one SHASUMS record (so such an action would fire) +nvm_download () { printf 'deadbeef sometarball\n'; } +# when nvm_get_checksum runs with that slug as its 4th argument +rm -f "${PROOF}" +nvm_get_checksum node std v1 'x" == $2) print $1} {system("touch${IFS}'"$PROOF"'")} #' tar.gz >/dev/null 2>&1 +# then the injected awk code must not execute +[ ! -e "${PROOF}" ] || die 'awk injection fires in nvm_get_checksum (slug interpolated into awk program text)' + +cleanup +echo 'nvm_get_checksum awk injection: passed'