The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes multiple leading special elements that could be interpreted in unexpected ways when they are sent to a downstream component.
View on MITREAs data is parsed, improperly handled multiple leading special elements may cause the process to take unexpected actions that result in an attack.
Developers should anticipate that multiple leading special elements 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.
Server allows remote attackers to bypass access restrictions for files via an HTTP request with a sequence of multiple / (slash) characters such as http://www.example.com///file/.
View DetailsCWE-161: Improper Neutralization of Multiple Leading Special Elements 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 multiple leading special elements that could be interpreted in unexpected ways when they are sent to a downstream component. As data is parsed, improperly handled multiple leading special elements may cause the process to take unexpected actions that result in an attack.
If exploited, CWE-161 (Improper Neutralization of Multiple Leading Special Elements) it can compromise Integrity, leading to outcomes such as Unexpected State.
Recommended mitigations for CWE-161 include: Developers should anticipate that multiple leading special elements 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-161 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-161, including CVE-2002-1238. 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-161 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.