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Description
The software does not neutralize or incorrectly neutralizes invalid characters or byte sequences in the middle of tag names, URI schemes, and other identifiers.
Some web browsers may remove these sequences, resulting in output that may have unintended control implications. For example, the software may attempt to remove a “javascript:” URI scheme, but a “java%00script:” URI may bypass this check and still be rendered as active javascript by some browsers, allowing XSS or other attacks.
Modes of Introduction:
– Implementation
Likelihood of Exploit:
Related Weaknesses
CWE-79
CWE-184
CWE-436
Consequences
Confidentiality, Integrity, Availability: Read Application Data, Execute Unauthorized Code or Commands
Potential Mitigations
Phase: Implementation
Effectiveness:
Description:
Phase: Implementation
Effectiveness: Defense in Depth
Description:
To help mitigate XSS attacks against the user’s session cookie, set the session cookie to be HttpOnly. In browsers that support the HttpOnly feature (such as more recent versions of Internet Explorer and Firefox), this attribute can prevent the user’s session cookie from being accessible to malicious client-side scripts that use document.cookie. This is not a complete solution, since HttpOnly is not supported by all browsers. More importantly, XMLHTTPRequest and other powerful browser technologies provide read access to HTTP headers, including the Set-Cookie header in which the HttpOnly flag is set.
CVE References
- CVE-2004-0595
- XSS filter doesn’t filter null characters before looking for dangerous tags, which are ignored by web browsers. Multiple Interpretation Error (MIE) and validate-before-cleanse.
