Weakness · Medium
CWE-473: PHP External Variable Modification
What it is
A PHP application does not properly protect against the modification of variables from external sources, such as query parameters or cookies. This can expose the application to numerous weaknesses that would not exist otherwise.
- Severity (our rating)
- Medium
- Likelihood of exploit
- Not rated by MITRE
- Introduced during
- Implementation
- Exploited in the wild
- 2 known exploited CVEs
What an attacker can do
- Modify Application Data (Integrity)
How to prevent it
Requirements
- Carefully identify which variables can be controlled or influenced by an external user, and consider adopting a naming convention to emphasize when externally modifiable variables are being used. An application should be reluctant to trust variables that have been initialized outside of its trust boundary. Ensure adequate checking is performed when relying on input from outside a trust boundary. Do not allow your application to run with register_globals enabled. If you implement a register_globals emulator, be extremely careful of variable extraction, dynamic evaluation, and similar issues, since weaknesses in your emulation could allow external variable modification to take place even without register_globals.
Exploited in the wild: 2 CVEs
Vulnerabilities caused by CWE-473 that attackers have used, from CISA's Known Exploited Vulnerabilities catalog, newest first.
H2 Security
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Start freeSource: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.