The product decodes the same input twice, which can limit the effectiveness of any protection mechanism that occurs in between the decoding operations.
View on MITRENo mitigation information available for this CWE.
No detection method information available for this CWE.
Forum software improperly URL decodes the highlight parameter when extracting text to highlight, which allows remote attackers to execute arbitrary PHP code by double-encoding the highlight value so that special characters are inserted into the result.
View DetailsXSS protection mechanism attempts to remove "/" that could be used to close tags, but it can be bypassed using double encoded slashes (%252F)
View DetailsBrowser executes HTML at higher privileges via URL with hostnames that are double hex encoded, which are decoded twice to generate a malicious hostname.
View DetailsCWE-174: Double Decoding of the Same Data is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product decodes the same input twice, which can limit the effectiveness of any protection mechanism that occurs in between the decoding operations.
If exploited, CWE-174 (Double Decoding of the Same Data) it can compromise Access Control, Confidentiality, Availability, Integrity and Other, leading to outcomes such as Bypass Protection Mechanism, Execute Unauthorized Code or Commands and Varies by Context.
CWE-174 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-174, including CVE-2004-1315, CVE-2004-1939, CVE-2001-0333, CVE-2004-1938 and CVE-2005-1945. 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-174 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.