Security restrictions bypass in Coturn

1) Security features bypass

EUVDB-ID: #VU49937

Risk: Medium

CVSSv3.1: 6.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-26262

CWE-ID: CWE-254 - Security Features

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists in the way the Coturn handles CONNECT requests with XOR-PEER-ADDRESS set to "0.0.0.0". A remote attacker can send specially crafted request to the affected server and force Coturn relay on the loopback addresses, such as 127.x.x.x and ::1, which is disabled by default.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

coTURN: 4.0.0.0 - 4.5.1.3

External links

http://github.com/coturn/coturn/blob/57180ab60afcaeb13537e69ae8cb8aefd8f3f546/ChangeLog#L48
http://github.com/coturn/coturn/commit/abfe1fd08d78baa0947d17dac0f7411c3d948e4d
http://github.com/coturn/coturn/security/advisories/GHSA-6g6j-r9rf-cm7p
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/G54UIUFTEC6RLPOISMB6FUW7456SBZC4/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/M4CJOPAQT43MYAFU3UROGLEXN3Z6RS4H/

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.