navidrome/utils
Adrián Sánchez Zapico a3f41fb422
sec(server): sanitize user-controlled filenames in Content-Disposition (#5895)
* sec(server): sanitize user-controlled filenames in Content-Disposition

Playlist export, Subsonic download and public share download built the
Content-Disposition header by interpolating a user-controlled name into a
quoted-string with fmt.Sprintf. A name containing a double quote closes the
string early and the rest is parsed as additional parameters, so a playlist
named `party"; filename="evil.html` yielded

    attachment; filename="party"; filename="evil.html.m3u"

letting whoever chose the name decide what the browser saves the download as.
The names come from playlists, album/artist names and media file tags.

Go's net/http already rewrites CR and LF in header values to spaces, so
response splitting was not reachable; parameter injection was.

Add str.ContentDispositionAttachment, which emits a sanitized ASCII-only
quoted `filename` plus an RFC 5987 `filename*` carrying the original UTF-8
name, and use it at all four call sites. The `filename*` parameter also fixes
non-ASCII names, which previously went out raw or were mangled by sanitizing.

Signed-off-by: zapisanchez <zapisanchez@gmail.com>

* fix(server): keep download names intact and sanitize filename*

Rework ContentDispositionAttachment after review. Names with no ASCII
letters now fall back to download.<ext> instead of a bare extension
(東京.mp3 gave filename="mp3"). filename* is built from the same
sanitized name as the ASCII fallback, so path separators, reserved
characters, control and bidi characters, and invalid UTF-8 no longer
reach it. The ASCII fallback transliterates accents and typographic
punctuation (Legião -> Legiao, She’s -> She's) through the existing
sanitize.Accents and str.Clear helpers, keeps leading dots, and only
trims trailing ones. Names are capped at 255 bytes, keeping the
extension.

Pure ASCII names now get only the quoted filename parameter, so the
header for them matches the previous output byte for byte. filename*
is encoded with mime.FormatMediaType instead of a hand-written RFC 5987
encoder. Adds tests for the M3U export and Subsonic download headers.

* fix(server): handle dot-only names and long fake extensions

A name made only of dots trimmed down to an empty filename. It now
falls back to download, like an empty stem does.

path.Ext treats anything after the last dot as the extension, so a long
suffix with no real extension was kept whole and replaced the stem with
download, going past the 255-byte cap. Suffixes longer than 16 bytes
are now treated as part of the stem and truncated with it.

Neither case is reachable from the current call sites, which always
append a short extension.

---------

Signed-off-by: zapisanchez <zapisanchez@gmail.com>
Co-authored-by: Deluan <deluan@navidrome.org>
2026-09-23 09:47:16 -04:00
..
cache fix(stream): abort the response when a transcoded stream is truncated (#6035) 2026-08-25 18:48:43 -04:00
chrono refactor: multiple syntax updates for Go 1.26 2026-05-19 18:02:36 -03:00
gg feat(subsonic): add structured sidecar lyrics support with OpenSubsonic v2 karaoke cues and agent layers (#5076) 2026-06-19 12:00:58 -04:00
gravatar feat(bfr): Big Refactor: new scanner, lots of new fields and tags, improvements and DB schema changes (#2709) 2025-02-19 20:35:17 -05:00
hasher refactor: run Go modernize (#5002) 2026-02-08 09:57:30 -05:00
httpclient fix(artwork): block private and loopback addresses in remote image fetches (#6181) 2026-09-20 20:46:46 -04:00
ioutils fix: handle UTF BOM in lyrics and playlist files (#4637) 2025-10-31 09:07:23 -04:00
jsoncommentstrip refactor(jsoncommentstrip): replace go-jsoncommentstrip with custom JSON comment stripping 2026-03-14 10:18:56 -04:00
merge Upgrade Go to 1.23 (#3190) 2024-08-19 17:47:54 -04:00
nanoid refactor(nanoid): replace gonanoid with custom nanoid implementation for ID generation 2026-03-13 21:06:26 -04:00
natural feat: add optional natural sort order for names and titles (#6015) 2026-08-23 14:31:37 -04:00
netguard fix(artwork): block private and loopback addresses in remote image fetches (#6181) 2026-09-20 20:46:46 -04:00
number chore(deps): remove direct dependency on golang.org/x/exp 2025-12-31 17:03:44 -05:00
pl chore: upgrade golangci-lint to 2.11 and fix lint issues 2026-03-06 19:23:47 -05:00
random refactor: run Go modernize (#5002) 2026-02-08 09:57:30 -05:00
req refactor(server): drop redundant error return from req.Strings parsing (#5812) 2026-07-18 19:30:04 -04:00
run refactor: rename chain package to run and update references 2025-06-14 17:19:06 -04:00
shellquote refactor(shellquote): replace go-shellquote with custom shell quoting implementation 2026-03-14 10:23:45 -04:00
singleton fix: assorted scanner, plugin, and server fixes from the Go 1.27 work (#6050) 2026-08-30 21:24:50 -04:00
slice perf(subsonic): speed up artist search3 deep-offset pagination (#5620) 2026-06-16 21:47:15 -04:00
str sec(server): sanitize user-controlled filenames in Content-Disposition (#5895) 2026-09-23 09:47:16 -04:00
context.go Refactored agents calling into its own struct 2021-06-08 17:00:02 -04:00
context_test.go Upgrade Ginkgo to V2 2022-07-26 16:53:17 -04:00
encrypt.go feat(bfr): Big Refactor: new scanner, lots of new fields and tags, improvements and DB schema changes (#2709) 2025-02-19 20:35:17 -05:00
encrypt_test.go Upgrade Ginkgo to V2 2022-07-26 16:53:17 -04:00
files.go feat(playlist): support #EXTALBUMARTURL directive and sidecar images (#5131) 2026-03-02 11:39:59 -05:00
files_test.go ci: run Go tests on Windows (#5380) 2026-04-19 13:16:47 -04:00
index_group_parser.go refactor: run Go modernize (#5002) 2026-02-08 09:57:30 -05:00
index_group_parser_test.go Upgrade Ginkgo to V2 2022-07-26 16:53:17 -04:00
limiter.go feat(bfr): Big Refactor: new scanner, lots of new fields and tags, improvements and DB schema changes (#2709) 2025-02-19 20:35:17 -05:00
time.go feat(smartplaylist): per-playlist refreshDelay for stable daily/weekly playlists (#5790) 2026-07-16 22:20:35 -04:00
time_test.go feat(smartplaylist): per-playlist refreshDelay for stable daily/weekly playlists (#5790) 2026-07-16 22:20:35 -04:00
utils_suite_test.go Upgrade Ginkgo to V2 2022-07-26 16:53:17 -04:00