Parsing...

ToUpperCase Improper Character Morphing

Checks for any special characters which are converted to something else when uppercased.

Fuzzer

Created byIDKdir

Created Jul 13, 2024

Updated May 27, 2025

Unable to render tweet button

Detecting browser...

CategoryJavaScript Syntax

VisibilityPublic

TypeJS

CharsetUTF-8

Template used:

var targets=['"','\'','<','/','>','\\']
if (targets.includes('$[chr]'.toUpperCase())) {
    log($[i]+' (normal) ($[chr] -> '+"$[chr]".toUpperCase()+')')
}

if (targets.includes('$[chr]'.toLocaleUpperCase())) {
    log($[i]+' (locale) ($[chr] -> '+"$[chr]".toLocaleUpperCase()+')')
}

Sample payloads

var targets=['"','\'','<','/','>','\\']
if (targets.includes('0x00'.toUpperCase())) {
    alert(0+' (normal) (0x00 -> '+"0x00".toUpperCase()+')')
}

if (targets.includes('0x00'.toLocaleUpperCase())) {
    alert(0+' (locale) (0x00 -> '+"0x00".toLocaleUpperCase()+')')
}