1. Data validation techniques include various methods used in preventing attackers from taking advantage of the vulnerabilities arising due to invalid inputs
  2. Canonicalization of input or encoding of the input that can be easily interpreted by the system is always safe

Character set that mostly cause trouble are:

  • Characters that have special meaning
  • Normal control characters (Values less than 32)
  • Characters with values higher than 127
  • Metacharacters

Data Validation Techniques (Cont’d)

Data validation techniques include some of the basic general strategies such as:

  • Encode Known Bad
    – Encoding the known bad entries within the code
  • Reject Known Bad
    – Do not let known bad entries to be entered into the system
  • Accepting Exact Match
    – Accepting a finite list of only known values
  • Known Good
    – If a finite list is not available, then use known good approach