If a server sends two Strict-Transport-Security (STS) headers for a single connection, they will be rejected as invalid and HTTP Strict Transport Security (HSTS) will not be enabled for the connection. This vulnerability affects Firefox < 55.
Si un servidor envía dos cabeceras Strict-Transport-Security (STS) para una única conexión, serán rechazadas com inválidas y no se habilitará HTTP Strict Transport Security (HSTS) para la conexión. La vulnerabilidad afecta a Firefox en versiones anteriores a la 55.
USN-3391-1 fixed vulnerabilities in Firefox. The update introduced a performance regression with WebExtensions. This update fixes the problem. Multiple security issues were discovered in Firefox. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit these to conduct cross-site scripting attacks, bypass sandbox restrictions, obtain sensitive information, spoof the origin of modal alerts, bypass same origin restrictions, read uninitialized memory, cause a denial of service via program crash or hang, or execute arbitrary code. Various other issues were also addressed.
