Improper Certificate Validation in Twisted Web

1) Improper Certificate Validation

EUVDB-ID: #VU33150

Risk: Medium

CVSSv4.0: 6.9 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-12855

CWE-ID: CWE-295 - Improper Certificate Validation

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

In words.protocols.jabber.xmlstream in Twisted through 19.2.1, XMPP support did not verify certificates when used with TLS, allowing an attacker to MITM connections.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Twisted Web: 19.2.0 - 19.2.1

CPE2.3

• cpe:2.3:a:twisted:twisted:19.2.0:*:*:*:*:*:*:*
• cpe:2.3:a:twisted:twisted:19.2.1:*:*:*:*:*:*:*

External links

https://lists.opensuse.org/opensuse-security-announce/2019-09/msg00013.html
https://lists.opensuse.org/opensuse-security-announce/2019-09/msg00028.html
https://github.com/twisted/twisted/pull/1147
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PLTZDMFBNFSJMBXYJNGJHENJA4H2TSMZ/
https://twistedmatrix.com/trac/ticket/9561
https://usn.ubuntu.com/4308-1/
https://usn.ubuntu.com/4308-2/
https://www.oracle.com/security-alerts/cpuapr2020.html

Q & A

Can this vulnerability be exploited remotely?

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