XML Denial of Service in Feedgen library for Python

1) Resource exhaustion

EUVDB-ID: #VU24823

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-5227

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied XML input. A remote attacker can trigger resource exhaustion and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Feedgenerator: 0.1 - 0.8.0

CPE2.3

• cpe:2.3:a:lkiesow:feedgenerator:0.1:*:*:*:*:python:*:*
• cpe:2.3:a:lkiesow:feedgenerator:0.2:*:*:*:*:python:*:*
• cpe:2.3:a:lkiesow:feedgenerator:0.2.1:*:*:*:*:python:*:*

External links

https://docs.microsoft.com/en-us/archive/msdn-magazine/2009/november/xml-denial-of-service-attacks-and-defenses
https://github.com/lkiesow/python-feedgen/commit/f57a01b20fa4aaaeccfa417f28e66b4084b9d0cf
https://github.com/lkiesow/python-feedgen/security/advisories/GHSA-g8q7-xv52-hf9f

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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