+
+ A server can use CORS
(Cross-Origin Resource Sharing) to relax the
+ restrictions imposed by the SOP
(Same-Origin Policy), allowing controlled, secure
+ cross-origin requests when necessary.
+
+ A server with an overly permissive CORS
configuration may inadvertently
+ expose sensitive data or lead to CSRF
which is an attack that allows attackers to trick
+ users into performing unwanted operations in websites they're authenticated to.
+
+
+
+ When the origin
is set to true
, it signifies that the server
+ is accepting requests from any
origin, potentially exposing the system to
+ CSRF attacks. This can be fixed using false
as origin value or using a whitelist.
+
+
+
+ On the other hand, if the origin
is
+ set to null
, it can be exploited by an attacker to deceive a user into making
+ requests from a null
origin form, often hosted within a sandboxed iframe.
+
+
+
+ If the origin
value is user controlled, make sure that the data
+ is properly sanitized.
+
+
+
+ In the example below, the server_1
accepts requests from any origin
+ since the value of origin
is set to true
.
+ And server_2
's origin is user-controlled.
+
+
+
+ In the example below, the server_1
CORS is restrictive so it's not
+ vulnerable to CSRF attacks. And server_2
's is using properly sanitized
+ user-controlled data.
+
+