XXE in Apache NiFi

1) XML External Entity injection

EUVDB-ID: #VU59049

Risk: Medium

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-44145

CWE-ID: CWE-611 - Improper Restriction of XML External Entity Reference ('XXE')

Exploit availability: No

Description

The vulnerability allows a remote user to gain access to sensitive information.

The vulnerability exists due to insufficient validation of user-supplied XML input within the TransformXML processor. A remote user can pass a specially crafted XML code to the affected application and view contents of arbitrary files on the system or initiate requests to external systems.

Successful exploitation of the vulnerability may allow an attacker to view contents of arbitrary file on the server or perform network scanning of internal and external infrastructure.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Apache Nifi: 0.1 - 1.15.0

CPE2.3

• cpe:2.3:a:apache_foundation:apache_nifi:0.1:*:*:*:*:*:*:*
• cpe:2.3:a:apache_foundation:apache_nifi:0.2:*:*:*:*:*:*:*
• cpe:2.3:a:apache_foundation:apache_nifi:0.2.1:*:*:*:*:*:*:*

External links

https://nifi.apache.org/security.html#1.15.1-vulnerabilities

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.