Adobe Flash Player before 13.0.0.241 and 14.x before 14.0.0.176 on Windows and OS X and before 11.2.202.400 on Linux, Adobe AIR before 14.0.0.178 on Windows and OS X and before 14.0.0.179 on Android, Adobe AIR SDK before 14.0.0.178, and Adobe AIR SDK & Compiler before 14.0.0.178 do not properly restrict the SWF file format, which allows remote attackers to conduct cross-site request forgery (CSRF) attacks against JSONP endpoints, and obtain sensitive information, via a crafted OBJECT element with SWF content satisfying the character-set requirements of a callback API, in conjunction with a manipulation involving a $ (dollar sign) or ( (open parenthesis) character. NOTE: this issue exists because of an incomplete fix for CVE-2014-4671.
Weakness
The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request.
Affected Software
Name |
Vendor |
Start Version |
End Version |
Adobe_air |
Adobe |
* |
14.0.0.137 (including) |
Adobe_air |
Adobe |
13.0.0.83 (including) |
13.0.0.83 (including) |
Adobe_air |
Adobe |
13.0.0.111 (including) |
13.0.0.111 (including) |
Adobe_air |
Adobe |
14.0.0.110 (including) |
14.0.0.110 (including) |
Potential Mitigations
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, use anti-CSRF packages such as the OWASP CSRFGuard. [REF-330]
- Another example is the ESAPI Session Management control, which includes a component for CSRF. [REF-45]
- Use the “double-submitted cookie” method as described by Felten and Zeller:
- When a user visits a site, the site should generate a pseudorandom value and set it as a cookie on the user’s machine. The site should require every form submission to include this value as a form value and also as a cookie value. When a POST request is sent to the site, the request should only be considered valid if the form value and the cookie value are the same.
- Because of the same-origin policy, an attacker cannot read or modify the value stored in the cookie. To successfully submit a form on behalf of the user, the attacker would have to correctly guess the pseudorandom value. If the pseudorandom value is cryptographically strong, this will be prohibitively difficult.
- This technique requires Javascript, so it may not work for browsers that have Javascript disabled. [REF-331]
References