What is CWE-918?
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
Analyzing data...
CWE-918: Server-Side Request Forgery (SSRF)
Data statistics
OWASP TOP 10:2025 RANK1 — A01:2025 — Broken Access Control
RELATED CVES (365 DAYS)1,059
ABSTRACTIONBase
Vulnerabilities mapped to CWE-918
1,059 vulnerabilities782.5% increase year over year
Vulnerabilities in CISA KEV for CWE-918
4 vulnerabilities
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
Characteristics
Alternate terms
- XSPA — Cross Site Port Attack
- SSRF — Server-Side Request Forgery
Modes of introduction
- Architecture and Design
- Implementation
Common consequences
| Impact | Scope | Explanation |
|---|---|---|
| Read Application Data | Confidentiality | — |
| Execute Unauthorized Code or Commands | Integrity | — |
| Bypass Protection Mechanism | Access Control | By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests. |
Detection methods
| Method | Approach | Effectiveness |
|---|---|---|
| Automated Static Analysis | Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.) | High |
Representative vulnerabilities
Below are representative vulnerabilities related to this CWE, prioritized by severity.
CWE™ Program, operated by The MITRE Corporation. Copyright © 2006–2026, The MITRE Corporation. The MITRE Corporation hereby grants you a non-exclusive, royalty-free license to use CWE for research, development, and commercial purposes. CWE Terms of Use.
Learn more
Run an in-depth assessment with complete web risk management
CyStack VulnScan continuously discovers assets, validates vulnerabilities, and helps security teams prioritize remediation across the organization.
Explore CyStack VulnScan
