CWE-1287: Improper Validation of Specified Type of Input

What is CWE-1287?

CWE-1287 is Improper Validation of Specified Type of Input. The flaw arises when the product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type. The database currently holds 44 vulnerabilities mapped to CWE-1287 and none of them are in the CISA Known Exploited Vulnerabilities catalog.

Analyzing data...

OWASP Top 10 Rank-
Related CVES (365 days)44
AbstractionBase
Likelihood of exploit-

Vulnerabilities mapped to CWE-1287

44 vulnerabilities47% increase year over year

No data

No vulnerability data in CISA KEV for CWE-1287

Official definition

ByMitre CWE

The product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type.

When input does not comply with the expected type, attackers could trigger unexpected errors, cause incorrect actions to take place, or exploit latent vulnerabilities that would not be possible if the input conformed with the expected type.

This weakness can appear in type-unsafe programming languages, or in programming languages that support casting or conversion of an input to another type.

Characteristics

Modes of introduction

  • Implementation

Common consequences

ImpactScopeExplanation
Varies by ContextOther-

Risk mitigations

  1. Input Validation · Implementation · Effectiveness: HighAssume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

Representative vulnerabilities

Below are representative vulnerabilities related to this CWE, prioritized by severity.

Sources (2)
MITRE CWE
CWE Terms of Use

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
More resources & insights

Explore more resources from CyStack

Website security reports

Review CyStack's security rating and practical recommendations for websites and edge assets.

Learn more

CyStack research

Explore cybersecurity research from our team of security specialists.

Learn more

Cybersecurity knowledge

Browse practical cybersecurity knowledge across CyStack's articles and guides.

Learn more