CVE-2020-262627.2HighCWE-441

CVE-2020-26262: Loopback bypass in Coturn

coturn

Fixed in 4.5.2 · Affected: coturn before 4.5.2 · Exploitation: possible (1 to 10%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

1.6%probability of exploitation in the next 30 days

75th percentile

050100

Higher than 75% of scored CVEs

7.2HighCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

coturn · coturn< 4.5.2

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Possible (1 to 10%). EPSS between 1% and 10%.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Unintended Proxy or Intermediary · Access Control
Vendor: coturn
Published: January 2021
Band: Possible (1 to 10%), January 2021

CoverageNo articles yet

No CyberSIXT article names CVE-2020-26262 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.