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Common Weakness Enumeration

A Community-Developed List of Software Weakness Types

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ID

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

Weakness ID: 82
Abstraction: Variant
Status: Incomplete
Presentation Filter:
+ Description

Description Summary

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

Extended Description

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.

+ Time of Introduction
  • Implementation
+ Applicable Platforms

Languages

All

+ Common Consequences
ScopeEffect
Confidentiality
Integrity
Availability

Technical Impact: Read application data; Execute unauthorized code or commands

+ Observed Examples
ReferenceDescription
Stored XSS in a guestbook application using a javascript: URI in a bbcode img tag.
javascript URI scheme in IMG tag.
javascript URI scheme in IMG tag.
javascript URI scheme in IMG tag.
javascript URI scheme in IMG tag.
javascript URI scheme in IMG tag.
javascript URI scheme in IMG tag.
javascript URI scheme in IMG tag.
+ Potential Mitigations

Phase: Implementation

Strategy: Output Encoding

Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.

The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.

Phase: Implementation

Strategy: Identify and Reduce Attack Surface

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.

Effectiveness: Defense in Depth

+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfWeakness VariantWeakness Variant83Improper Neutralization of Script in Attributes in a Web Page
Development Concepts (primary)699
Research Concepts (primary)1000
ChildOfCategoryCategory990SFP Secondary Cluster: Tainted Input to Command
Software Fault Pattern (SFP) Clusters (primary)888
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERScript in IMG tags
Software Fault PatternsSFP24Tainted input to command
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVERExternally Mined
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigitalExternal
updated Time_of_Introduction
2008-09-08CWE Content TeamMITREInternal
updated Relationships, Taxonomy_Mappings
2008-10-14CWE Content TeamMITREInternal
updated Description
2009-05-27CWE Content TeamMITREInternal
updated Description, Name
2009-10-29CWE Content TeamMITREInternal
updated Relationships
2009-12-28CWE Content TeamMITREInternal
updated Observed_Examples
2010-06-21CWE Content TeamMITREInternal
updated Description, Name, Potential_Mitigations
2011-06-01CWE Content TeamMITREInternal
updated Common_Consequences
2012-05-11CWE Content TeamMITREInternal
updated Relationships
2012-10-30CWE Content TeamMITREInternal
updated Potential_Mitigations
2014-07-30CWE Content TeamMITREInternal
updated Relationships, Taxonomy_Mappings
2017-05-03CWE Content TeamMITREInternal
updated Related_Attack_Patterns
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Script in IMG Tags
2009-05-27Failure to Sanitize Script in Attributes of IMG Tags in a Web Page
2010-06-21Improper Sanitization of Script in Attributes of IMG Tags in a Web Page

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Page Last Updated: May 05, 2017