Improper Sanitization of Macro Symbols
Weakness ID: 152 (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 macro symbols when they are sent to a downstream component.
+ Time of Introduction
  • Implementation
+ Applicable Platforms



+ Observed Examples
CVE-2002-0770Server trusts client to expand macros, allows macro characters to be expanded to trigger resultant infoleak.
CVE-2008-2018Attacker can obtain sensitive information from a database by using a comment containing a macro, which inserts the data during expansion.
+ Potential Mitigations

Developers should anticipate that macro symbols 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
+ Research Gaps


+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERMacro Symbol
+ Content History
Submission DateSubmitterOrganizationSource
PLOVERExternally Mined
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigitalExternal
updated Potential Mitigations, Time of Introduction
2008-09-08CWE Content TeamMITREInternal
updated Relationships, Observed Example, Taxonomy Mappings
2009-03-10CWE Content TeamMITREInternal
updated Description, Name
2009-07-27CWE Content TeamMITREInternal
updated Potential Mitigations
Previous Entry Names
Change DatePrevious Entry Name
2008-01-30Macro Symbol
2008-04-11Failure to Remove Macro Symbol
2009-03-10Failure to Sanitize Macro Symbol