The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as whitespace when they are sent to a downstream component.
View on MITREThis can include space, tab, etc.
Developers should anticipate that whitespace will be injected/removed/manipulated in the input vectors of their product. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
No detection method information available for this CWE.
MIE. virus protection bypass with RFC violations involving extra whitespace, or missing whitespace.
View DetailsCPU consumption with MIME headers containing lines with many space characters, probably due to algorithmic complexity (RESOURCE.AMP.ALG).
View DetailsCWE-156: Improper Neutralization of Whitespace is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as whitespace when they are sent to a downstream component. This can include space, tab, etc.
If exploited, CWE-156 (Improper Neutralization of Whitespace) it can compromise Integrity, leading to outcomes such as Unexpected State.
Recommended mitigations for CWE-156 include: Developers should anticipate that whitespace will be injected/removed/manipulated in the input vectors of their product. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
CWE-156 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.
MITRE documents real CVEs mapped to CWE-156, including CVE-2002-0637, CVE-2004-0942 and CVE-2003-1015. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.
A CWE (Common Weakness Enumeration) like CWE-156 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.