Vulnerability Database

328,411

Total vulnerabilities in the database

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.

  • Published: Jan 13, 2021
  • Updated: Nov 16, 2025
  • CVE: CVE-2020-26262
  • Severity: High
  • Exploit:

CVSS v3:

  • Severity: High
  • Score: 7.2
  • AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

CVSS v2:

  • Severity: Medium
  • Score: 6.4
  • AV:N/AC:L/Au:N/C:P/I:P/A:N

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.