Improper Sanitization of Comment Delimiters
Weakness ID: 151 (Weakness Variant)Status: Draft
+ Description

Description Summary

The software receives input from an upstream component, but it does not sanitize or incorrectly sanitizes special elements that could be interpreted as comment delimiters when they are sent to a downstream component.
+ Time of Introduction
  • Implementation
+ Applicable Platforms

Languages

All

+ Observed Examples
ReferenceDescription
CVE-2002-0001Mail client command execution due to improperly terminated comment in address list.
CVE-2004-0162MIE. RFC822 comment fields may be processed as other fields by clients.
CVE-2004-1686Well-placed comment bypasses security warning.
CVE-2005-1909Information hiding using a manipulation involving injection of comment code into product. Note: these vulnerabilities are likely vulnerable to more general XSS problems, although a regexp might allow ">!--" while denying most other tags.
CVE-2005-1969Information hiding using a manipulation involving injection of comment code into product. Note: these vulnerabilities are likely vulnerable to more general XSS problems, although a regexp might allow "<!--" while denying most other tags.
+ Potential Mitigations

Developers should anticipate that comments will be injected/removed/manipulated in the input vectors of their software system. Use an appropriate combination of black lists and white lists to ensure only valid, expected and appropriate input is processed by the system.

Phase: Architecture and Design

Assume all input is malicious. Use a standard input validation mechanism to validate all input for length, type, syntax, and business rules before accepting the data to be displayed or stored. Use an "accept known good" validation strategy.

Use and specify a strong output encoding (such as ISO 8859-1 or UTF 8).

Do not rely exclusively on blacklist validation to detect malicious input or to encode output. There are too many variants to encode a character; you're likely to miss some variants.

Inputs should be decoded and canonicalized to the application's current internal representation before being validated. Make sure that your application does not decode the same input twice. Such errors could be used to bypass whitelist schemes by introducing dangerous inputs after they have been checked.

+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfWeakness ClassWeakness Class138Improper Sanitization of Special Elements
Development Concepts (primary)699
Research Concepts (primary)1000
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERComment Element
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVERExternally Mined
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigitalExternal
updated Potential Mitigations, Time of Introduction
2008-09-08CWE Content TeamMITREInternal
updated Relationships, Taxonomy Mappings
2009-03-10CWE Content TeamMITREInternal
updated Description, Name
2009-07-27CWE Content TeamMITREInternal
updated Observed Examples, Potential Mitigations
Previous Entry Names
Change DatePrevious Entry Name
2008-01-30Comment Element
2008-04-11Failure to Remove Comment Element
2009-03-10Failure to Sanitize Comment Element