A flaw was found in the way Netty’s CookieDecoder method validated cookie name and value characters. An attacker could use this flaw to bypass the httpOnly flag on sensitive cookies.
Upstream patch:
https://github.com/slandelle/netty/commit/800555417e77029dcf8a31d7de44f27b5a8f79b8
External References:
https://www.playframework.com/security/vulnerability/CVE-2015-2156-HttpOnlyBypass http://engineering.linkedin.com/security/look-netty%E2%80%99s-recent-security-update-cve%C2%AD-2015%C2%AD-2156