Missing message authentication in the meta-protocol in Tinc VPN version 1.0.34 and earlier allows a man-in-the-middle attack to disable the encryption of VPN packets.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Missing message authentication in the meta-protocol in Tinc VPN version 1.0.34 and earlier allows a man-     in-the-middle attack to disable the encryption of VPN packets. (CVE-2018-16758)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - tinc before 1.0.30 has a broken authentication protocol, without even a partial mitigation.
    (CVE-2018-16737)

  - tinc 1.0.30 through 1.0.34 has a broken authentication protocol, although there is a partial mitigation.
    This is fixed in 1.1. (CVE-2018-16738)

  - Missing message authentication in the meta-protocol in Tinc VPN version 1.0.34 and earlier allows a man-
    in-the-middle attack to disable the encryption of VPN packets. (CVE-2018-16758)

Security fix for CVE-2018-16737, CVE-2018-16738, CVE-2018-16758

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

tinc-vpn.org reports :

The authentication protocol allows an oracle attack that could potentially be exploited.

If a man-in-the-middle has intercepted the TCP connection it might be able to force plaintext UDP packets between two nodes for up to a PingInterval period.

Several vulnerabilities were discovered in tinc, a Virtual Private Network (VPN) daemon. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CVE-2018-16738     Michael Yonli discovered a flaw in the implementation of     the authentication protocol that could allow a remote     attacker to establish an authenticated, one-way     connection with another node.

  - CVE-2018-16758     Michael Yonli discovered that a man-in-the-middle that     has intercepted a TCP connection might be able to     disable encryption of UDP packets sent by a node.

ID	Name	Product	Family	Severity
254211	Linux Distros Unpatched Vulnerability : CVE-2018-16758	Nessus	Misc.	medium
424551	Alpine: multiple tinc packages: security update to 1.0.35-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	medium
424551	Alpine: multiple tinc packages: security update to 1.0.35-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	medium
120712	Fedora 29 : tinc (2018-afae5e8438)	Nessus	Fedora Local Security Checks	medium
120335	Fedora 28 : tinc (2018-31c2a0b2ea)	Nessus	Fedora Local Security Checks	medium
118024	FreeBSD : tinc -- Buffer overflow (a4eb38ea-cc06-11e8-ada4-408d5cf35399)	Nessus	FreeBSD Local Security Checks	medium
117958	Debian DSA-4312-1 : tinc - security update	Nessus	Debian Local Security Checks	medium

Detections

Analytics

CVE-2018-16758

medium

Tenable Plugins

medium

medium

medium

medium

medium

medium

medium