The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes NUL characters or null bytes when they are sent to a downstream component.
View on MITREAs data is parsed, an injected NUL character or null byte may cause the product to believe the input is terminated earlier than it actually is, or otherwise cause the input to be misinterpreted. This could then be used to inject potentially dangerous input that occurs after the null byte or otherwise bypass validation routines and other protection mechanisms.
Developers should anticipate that null characters or null bytes 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.
Web server allows remote attackers to view the source code for CGI programs via a null character (%00) at the end of a URL.
View DetailsWeb server earlier allows allows remote attackers to bypass access restrictions, list directory contents, and read source code by inserting a null character (%00) in the URL.
View DetailsLogging system allows an attacker to cause a denial of service (hang) by causing null bytes to be placed in log messages.
View DetailsWeb server allows source code for executable programs to be read via a null character (%00) at the end of a request.
View DetailsProtection mechanism for limiting file access can be bypassed using a null character (%00) at the end of the directory name.
View DetailsApplication server allows remote attackers to read JSP source code via an encoded null byte in an HTTP GET request, which causes the server to send the .JSP file unparsed.
View DetailsXSS protection mechanism only checks for sequences with an alphabetical character following a (<), so a non-alphabetical or null character (%00) following a < may be processed.
View DetailsDecoding function in proxy allows regular expression bypass in ACLs via URLs with null characters.
View DetailsCWE-158: Improper Neutralization of Null Byte or NUL Character 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 NUL characters or null bytes when they are sent to a downstream component. As data is parsed, an injected NUL character or null byte may cause the product to believe the input is terminated earlier than it actually is, or otherwise cause the input to be misinterpreted. This could then be used to inject potentially dangerous input that occurs after the null byte or otherwise bypass validation routines and other protection mechanisms.
If exploited, CWE-158 (Improper Neutralization of Null Byte or NUL Character) it can compromise Integrity, leading to outcomes such as Unexpected State.
Recommended mitigations for CWE-158 include: Developers should anticipate that null characters or null bytes 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-158 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-158, including CVE-2008-1284, CVE-2005-2008, CVE-2005-3293, CVE-2005-2061 and CVE-2002-1774. 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-158 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.