Double Decoding of the Same Data
CWE-174
The product decodes the same input twice.
We track 2 vulnerabilities of this type. 100% are rated high or critical, and the average CVSS score is 8.4.
How this weakness is prevented
- Architecture and Design: Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
- Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
Latest Double Decoding of the Same Data vulnerabilities
- 9.4 Critical severity
LiteSpeed Web Server: Double Decoding of the Same Data
LiteSpeed Web Server (LSWS) before 6.3.7 build 1 mishandles internal redirect URL validation in a certain "corner case" of %252e%252e double decoding, letting a low-privileged tenant execute code in the context of a different account.
- 7.5 High severity
fast-uri: Double Decoding of the Same Data
fast-uri is a URI parser for Node.js. It decodes percent escapes in a hostname during parsing and then decodes the parsed hostname a second time during authority recomposition, so a single call to normalize or resolve can turn nested percent-encoded input into