CVE Vulnerability

CVE-2020-26262

Coturn is free open source implementation of TURN and STUN Server. Coturn before version 4.5.2 by default does not allow peers to connect and relay packets to loopback addresses in the range of `127.x.x.x`. However, it was observed that when sending a `CONNECT` request with the `XOR-PEER-ADDRESS` value of `0.0.0.0`, a successful response was received and subsequently, `CONNECTIONBIND` also received a successful response. Coturn then is able to relay packets to the loopback interface. Additionally, when coturn is listening on IPv6, which is default, the loopback interface can also be reached by making use of either `[::1]` or `[::]` as the peer address. By using the address `0.0.0.0` as the peer address, a malicious user will be able to relay packets to the loopback interface, unless `--denied-peer-ip=0.0.0.0` (or similar) has been specified. Since the default configuration implies that loopback peers are not allowed, coturn administrators may choose to not set the `denied-peer-ip` setting. The issue patched in version 4.5.2. As a workaround the addresses in the address block `0.0.0.0/8`, `[::1]` and `[::]` should be denied by default unless `--allow-loopback-peers` has been specified.

6.4 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 10 / Impact : 4.9

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact NONE

Scope

7.2 /10

CVSS v3.0 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References
Link Resource
https://github.com/coturn/coturn/commit/abfe1fd08d78baa0947d17dac0f7411c3d948e4d Patch Third Party Advisory
https://github.com/coturn/coturn/blob/57180ab60afcaeb13537e69ae8cb8aefd8f3f546/ChangeLog#L48 Release Notes Third Party Advisory
https://github.com/coturn/coturn/security/advisories/GHSA-6g6j-r9rf-cm7p Exploit Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/G54UIUFTEC6RLPOISMB6FUW7456SBZC4/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/M4CJOPAQT43MYAFU3UROGLEXN3Z6RS4H/ Mailing List Third Party Advisory
Configurations

Configuration 1

cpe:2.3:a:coturn_project:coturn:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
Information

Published : 2021-01-13 07:15

Updated : 2022-01-01 06:12

NVD link : CVE-2020-26262

Mitre link : CVE-2020-26262

Products Affected
No products.
CWE
CWE-441

CWE-682