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.
Attacker can obtain sensitive information from a
database by using a comment containing a macro, which inserts the data
during expansion.
Potential Mitigations
Phase
Description
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.
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.
Description
