TeX Live through 20170524 does not validate strings before launching the program specified by the BROWSER environment variable, which might allow remote attackers to conduct argument-injection attacks via a crafted URL, related to linked_scripts/context/stubs/unix/mtxrun, texmf-dist/scripts/context/stubs/mswin/mtxrun.lua, and texmf-dist/tex/luatex/lualibs/lualibs-os.lua.