Decrypts the password of some China Telecom's routers (e.g. MR622-KK).

telecom-decrypt.js

// At very first, you need to obtain the encrypted password from (response).BASEINFO.baseinfoSet_USERPASSWORD at http://192.168.1.1:8080/cgi-bin/baseinfoSet.cgi.

// The relation of the numbers and their corresponding characters.
const table = [[69,"A"],[70,"B"],[71,"C"],[72,"D"],[73,"E"],[74,"F"],[75,"G"],[76,"H"],[77,"I"],[78,"J"],[79,"K"],[80,"L"],[81,"M"],[82,"N"],[83,"O"],[84,"P"],[85,"Q"],[86,"R"],[87,"S"],[88,"T"],[89,"U"],[90,"V"],[65,"W"],[66,"X"],[67,"Y"],[68,"Z"],[101,"a"],[102,"b"],[103,"c"],[104,"d"],[105,"e"],[106,"f"],[107,"g"],[108,"h"],[109,"i"],[110,"j"],[111,"k"],[112,"l"],[113,"m"],[114,"n"],[115,"o"],[116,"p"],[117,"q"],[118,"r"],[119,"s"],[120,"t"],[121,"u"],[122,"v"],[97,"w"],[98,"x"],[99,"y"],[100,"z"],[48,"0"],[49,"1"],[50,"2"],[51,"3"],[52,"4"],[53,"5"],[54,"6"],[55,"7"],[56,"8"],[57,"9"],[91,"["],[93,"]"],[33,"!"],[64,"@"],[35,"#"],[36,"$"],[37,"%"],[94,"^"],[42,"*"],[40,"("],[41,")"],[95,"_"],[43,"+"],[123,"{"],[125,"}"],[124,"|"],[59,";"],[58,":"],[46,"."],[44,","],[47,"/"],[63,"?"],[null,null]];

// Decryption function.
const d = p => p.split('&').map(c => {
    for(let [code, char] of table)
        if(code === parseInt(c)) return char;
}).join('');

// Decrypt the password.
console.log(d(`71&89&69&104&113&109&114`)); // CUAdmin

If you'd like to make the process easier, you can simply paste and run the code below in the cgi page using DevTools mentioned above:

const table = [[69,"A"],[70,"B"],[71,"C"],[72,"D"],[73,"E"],[74,"F"],[75,"G"],[76,"H"],[77,"I"],[78,"J"],[79,"K"],[80,"L"],[81,"M"],[82,"N"],[83,"O"],[84,"P"],[85,"Q"],[86,"R"],[87,"S"],[88,"T"],[89,"U"],[90,"V"],[65,"W"],[66,"X"],[67,"Y"],[68,"Z"],[101,"a"],[102,"b"],[103,"c"],[104,"d"],[105,"e"],[106,"f"],[107,"g"],[108,"h"],[109,"i"],[110,"j"],[111,"k"],[112,"l"],[113,"m"],[114,"n"],[115,"o"],[116,"p"],[117,"q"],[118,"r"],[119,"s"],[120,"t"],[121,"u"],[122,"v"],[97,"w"],[98,"x"],[99,"y"],[100,"z"],[48,"0"],[49,"1"],[50,"2"],[51,"3"],[52,"4"],[53,"5"],[54,"6"],[55,"7"],[56,"8"],[57,"9"],[91,"["],[93,"]"],[33,"!"],[64,"@"],[35,"#"],[36,"$"],[37,"%"],[94,"^"],[42,"*"],[40,"("],[41,")"],[95,"_"],[43,"+"],[123,"{"],[125,"}"],[124,"|"],[59,";"],[58,":"],[46,"."],[44,","],[47,"/"],[63,"?"],[null,null]];const d = p => p.split('&').map(c => {for(let [code, char] of table)if(code === parseInt(c)) return char;}).join('');console.log(d(JSON.parse(document.body.innerText).BASEINFOSET.baseinfoSet_TELECOMPASSWORD));

where I merely replaced the encrypted string with the actual encrypted string.