webhard

Hard 3

spbctf

XSS challenge with strict whitelist filter allowing only 20 characters. Solution uses JSFuck-style encoding to construct prompt("sibears") from primitives like true/false/undefined strings, function toString representations, and Number.toString(36) for missing letters.

$ ls tags/ techniques/

filter_bypass xss javascript jsfuck string_construction whitelist_bypass function_constructor tostring_radix

jsfuck_encodingwhitelist_filter_bypasstype_coercion_string_extractionfunction_constructor_rcetostring_radix_char_generation

Analysis

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

$ python3 exploit.py --target 192.168.1.1 --port 8080
[*] Connecting to target...
[+] Shell obtained!

Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

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