SAP Knowledge Warehouse <= 7.50 “SAPIrExtHelp” Reflected XSS
Mar 17, 2022 · By Julien Ahrens
ADVISORY INFORMATION
- Product: SAP Knowledge Warehouse
- Vendor URL: https://www.sap.com
- Type: Cross-Site Scripting [CWE-79]
- Date found: 2021-09-21
- Date published: 2022-03-17
- CVSSv3 Score: 6.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N)
- CVE: CVE-2021-42063
CREDITS
This vulnerability was discovered and researched by Julien Ahrens from RCE Security.
VERSIONS AFFECTED
SAP Knowledge Warehouse - versions 7.30, 7.31, 7.40, 7.50
INTRODUCTION
The SAP Knowledge Warehouse (SAP KW) is the SAP Solution for all the material used in training, documentation and handbooks.
(from the vendor’s homepage)
VULNERABILITY DETAILS
The endpoint at /SAPIrExtHelp is vulnerable to an unauthenticated reflected Cross-Site Scripting vulnerability when user-supplied input to the URI is processed by the web application. Since the application does not properly validate and sanitize this input, it is possible to place arbitrary script code onto the same page.
The following Proof-of-Concept triggers this vulnerability:
/SAPIrExtHelp/random/%22%3e%3c%53%56%47%20%4f%4e%4c%4f%41%44%3d%26%23%39%37%26%23%31%30%38%26%23%31%30%31%26%23%31%31%34%26%23%31%31%36%28%26%23%78%36%34%26%23%78%36%66%26%23%78%36%33%26%23%78%37%35%26%23%78%36%64%26%23%78%36%35%26%23%78%36%65%26%23%78%37%34%26%23%78%32%65%26%23%78%36%34%26%23%78%36%66%26%23%78%36%64%26%23%78%36%31%26%23%78%36%39%26%23%78%36%65%29%3e.asp
RISK
To successfully exploit this vulnerability, an unauthenticated or authenticated user must be tricked into visiting an arbitrary website / link.
The vulnerability can be used to temporarily embed arbitrary script code into the context of the web interface, which offers a wide range of possible attacks such as redirecting the user to a malicious page, spoofing content on the page or attacking the browser and its plugins.
SOLUTION
Update SAP Knowledge Warehouse to the latest version.
REPORT TIMELINE
- 2021-09-21: Discovery of the vulnerability
- 2021-09-21: Contacted the vendor via their contact mail address
- 2021-09-21: Vendor response
- 2021-10-05: Requested status update from vendor
- 2021-10-06: Vendor acknowledges the vulnerability
- 2021-10-26: Requested status update from vendor
- 2021-10-27: Vendor states that they are still working on the issue
- 2021-11-04: CVE requested from SAP (responsible CNA)
- 2021-11-10: Vendor refuses to assign a CVE because they only assign CVEs when a security fix gets released
- 2021-11-10: Vendor asks not to disclose any details related to this bug by referring to their legal terms
- 2021-11-10: Complained about vendor’s legal terms which hold researchers accountable for “any harm to SAP users”
- 2021-11-10: Asked for the release date of the patch
- 2021-11-10: Vendor refuses to provide the release date due to “legal perspectives”
- 2021-11-10: Told the vendor that I do not agree to their legal terms and therefore all future vulnerabilities will be disclosed without prior notification
- 2021-11-21: No vendor response
- 2021-11-21: Asked for a status update
- 2021-11-23: Vendor wants to have a phone call instead
- 2021-11-23: Rejected the phone call due to their squishy legal terms
- 2021-11-29: Vendor provides the assigned CVE-2021-42063
- 2021-11-29: Vendor asks not to release any details until December patch day (14th)
- 2021-12-13: Vendor provides information on the security note for December patch day
- 2021-12-13: Vendor asks for a 3-month grace period before doing the disclosure
- 2022-03-15: Sent notification about the upcoming public disclosure on 2022-03-17
- 2022-03-17: Public disclosure