CWE-290: Authentication Bypass by Spoofing
Official CWE-290 CWE context with Glexia analysis, remediation guidance, related CVEs, and ATT&CK context.
Glexia's Take
CWE-290: Authentication Bypass by Spoofing
Authentication Bypass by Spoofing represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Access Control: Bypass Protection Mechanism,Gain Privileges or Assume Identity: This weakness can allow an attacker to access resources which are not otherwise accessible without proper authentication.
Developer Pattern
CWE-290 is the kind of defect developers can usually prevent with explicit validation, safer framework defaults, and tests that exercise hostile input or unsafe state transitions.
Confidence
high confidence from CWE-290, 4.20.
Official CWE Definition
CWE-290: Authentication Bypass by Spoofing
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- The following code authenticates users. The authentication mechanism implemented relies on an IP address for source validation. If an attacker is able to spoof the IP, they may be able to bypass the authentication mechanism.
- Both of these examples check if a request is from a trusted address before responding to the request. The code only verifies the address as stored in the request packet. An attacker can spoof this address, thus impersonating a trusted client.
- The following code samples use a DNS lookup in order to decide whether or not an inbound request is from a trusted host. If an attacker can poison the DNS cache, they can gain trusted status. IP addresses are more reliable than DNS names, but they can also be spoofed. Attackers can easily forge the source IP address of the packets they send, but response packets will return to the forged IP address. To see the response packets, the attacker has to sniff the traffic between the victim machine and the forged IP address. In order to accomplish the required sniffing, attackers typically attempt to locate themselves on the same subnet as the victim machine. Attackers may be able to circumvent this requirement by using source routing, but source routing is disabled across much of the Internet today. In summary, IP address verification can be a useful part of an authentication scheme, but it should not be the single factor required for authentication.
Remediation
- Use safe APIs
- Centralize the control
- Add regression tests
- Review logs and telemetry for attempted abuse
Detection
- Code review
- SAST
- DAST
- Focused regression tests
Mappings
Related CVEs, CWEs, and ATT&CK context
Related CWEs
- CWE-1390: Weak Authentication
- CWE-287: Improper Authentication
- CWE-291: Reliance on IP Address for Authentication
- CWE-293: Using Referer Field for Authentication
- CWE-350: Reliance on Reverse DNS Resolution for a Security-Critical Action
- CWE-358: Improperly Implemented Security Check for Standard
- CWE-602: Client-Side Enforcement of Server-Side Security
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.