Impact
With trailingSlash: 'always' configured, the @astrojs/node standalone server's static file handler appends a trailing slash to request paths and issues a 301 redirect. Paths beginning with /\ (slash-backslash) were not recognized as internal paths, so the handler would echo the raw path back in the Location header. Because browsers treat \ as / per the WHATWG URL specification, the resulting redirect could resolve to an external host.
Preconditions:
trailingSlash: 'always' must be set (non-default; the default is 'ignore')- The request path must not have a file extension in its final segment
- An attacker must deliver the crafted link to a user
Patches
Fixed by treating backslash-prefixed paths the same as //-prefixed paths in isInternalPath(), so they are no longer rewritten with a trailing slash.
Workarounds
Use the default trailingSlash: 'ignore' setting, which does not issue trailing-slash redirects in the static file handler.
References
iaohkut-from-NightWolf-Team Reporter
Impact
With
trailingSlash: 'always'configured, the@astrojs/nodestandalone server's static file handler appends a trailing slash to request paths and issues a301redirect. Paths beginning with/\(slash-backslash) were not recognized as internal paths, so the handler would echo the raw path back in theLocationheader. Because browsers treat\as/per the WHATWG URL specification, the resulting redirect could resolve to an external host.Preconditions:
trailingSlash: 'always'must be set (non-default; the default is'ignore')Patches
Fixed by treating backslash-prefixed paths the same as
//-prefixed paths inisInternalPath(), so they are no longer rewritten with a trailing slash.Workarounds
Use the default
trailingSlash: 'ignore'setting, which does not issue trailing-slash redirects in the static file handler.References