Security
Using PHP features that are known to be exploitable or non-secure can lead to remote code execution or weak cryptography. As a developer, you should avoid using features that introduce vulnerabilities in your code.
PHP functions to avoid
The following is a list of PHP functions that are known to be vulnerable and exploitable. Avoid using these functions in your code.
eval
- Usingeval
is considered bad practice because of its ability to execute arbitrary PHP code.serialize
/unserialize
- Attackers can create an exploit for these functions by passing a string with a serialized arbitrary object to theunserialize
function to run arbitrary code.md5
- The algorithm for this function is known to have cryptographic weaknesses. You should never use this function for hashing passwords or any other sensitive data.srand
- Using a predetermined number to seed the random number generator results in a predictable sequence of numbers.mt_srand
- This function is a pseudo-random number generator (PRNG) and is not cryptographically secure.
Standard PHP library classes to avoid
ArrayObject
- UsingArrayObject
class is not recommended because it containsunserialize
method, which attackers can use to create an exploit.If you need to use the
ArrayObject
class, override theserialize
/unserialize
methods so that they use secure logic. Convert objects into arrays to serialize them, and reconstruct the objects using arrays during unserialization.You can use Serialize Library in framework for a secure way of serializing/unserializing data.