Mozilla Foundation Security Advisory 2015-37
CORS requests should not follow 30x redirections after preflight
- Announced
- March 31, 2015
- Reporter
- Christoph Kerschbaumer, Muneaki Nishimura
- Impact
- High
- Products
- Firefox, Firefox ESR, Firefox OS, SeaMonkey, Thunderbird
- Fixed in
-
- Firefox 37
- Firefox ESR 31.6
- Firefox OS 2.2
- SeaMonkey 2.35
- Thunderbird 31.6
Description
Mozilla developer Christoph Kerschbaumer discovered an issue
while investigating Mozilla
Foundation Security Advisory 2015-03, previously reported by security
researcher Muneaki Nishimura. This flaw was that a cross-origin
resource sharing (CORS) request should not follow 30x redirections after
preflight according to the specification. This only affects
sendBeacon() requests but could allow for a potential Cross-site
request forgery (XSRF) attack from malicious websites.
In general this flaw cannot be exploited through email in the Thunderbird product because scripting is disabled, but is potentially a risk in browser or browser-like contexts.