CWE

CWE-82 – Improper Neutralization of Script in Attributes of IMG Tags in a Web Page

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Description

The web application does not neutralize or incorrectly neutralizes scripting elements within attributes of HTML IMG tags, such as the src attribute.

Attackers can embed XSS exploits into the values for IMG attributes (e.g. SRC) that is streamed and then executed in a victim’s browser. Note that when the page is loaded into a user’s browsers, the exploit will automatically execute.

Modes of Introduction:

– Implementation

Likelihood of Exploit:

 

Related Weaknesses

CWE-83

 

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-2006-3211
    • Stored XSS in a guestbook application using a javascript: URI in a bbcode img tag.