Vulnerabilities > CVE-2018-16758 - Missing Authentication for Critical Function vulnerability in multiple products

047910
CVSS 5.9 - MEDIUM
Attack vector
NETWORK
Attack complexity
HIGH
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
NONE
Availability impact
NONE
network
high complexity
tinc-vpn
debian
starwindsoftware
CWE-306
nessus

Summary

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.

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Choosing a Message/Channel Identifier on a Public/Multicast Channel
    Attackers aware that more data is being fed into a multicast or public information distribution means can 'select' information bound only for another client, even if the distribution means itself forces users to authenticate in order to connect initially. Doing so allows the attacker to gain access to possibly privileged information, possibly perpetrate other attacks through the distribution means by impersonation. If the channel/message being manipulated is an input rather than output mechanism for the system, (such as a command bus), this style of attack could change its identifier from a less privileged to more so privileged channel or command.
  • Using Unpublished Web Service APIs
    An attacker searches for and invokes Web Services APIs that the target system designers did not intend to be publicly available. If these APIs fail to authenticate requests the attacker may be able to invoke services and/or gain privileges they are not authorized for.
  • Manipulating Writeable Terminal Devices
    This attack exploits terminal devices that allow themselves to be written to by other users. The attacker sends command strings to the target terminal device hoping that the target user will hit enter and thereby execute the malicious command with their privileges. The attacker can send the results (such as copying /etc/passwd) to a known directory and collect once the attack has succeeded.
  • Cross Site Request Forgery (aka Session Riding)
    An attacker crafts malicious web links and distributes them (via web pages, email, etc.), typically in a targeted manner, hoping to induce users to click on the link and execute the malicious action against some third-party application. If successful, the action embedded in the malicious link will be processed and accepted by the targeted application with the users' privilege level. This type of attack leverages the persistence and implicit trust placed in user session cookies by many web applications today. In such an architecture, once the user authenticates to an application and a session cookie is created on the user's system, all following transactions for that session are authenticated using that cookie including potential actions initiated by an attacker and simply "riding" the existing session cookie.

Nessus

  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_A4EB38EACC0611E8ADA4408D5CF35399.NASL
    descriptiontinc-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.
    last seen2020-06-01
    modified2020-06-02
    plugin id118024
    published2018-10-10
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/118024
    titleFreeBSD : tinc -- Buffer overflow (a4eb38ea-cc06-11e8-ada4-408d5cf35399)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-AFAE5E8438.NASL
    descriptionSecurity 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.
    last seen2020-06-05
    modified2019-01-03
    plugin id120712
    published2019-01-03
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/120712
    titleFedora 29 : tinc (2018-afae5e8438)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-31C2A0B2EA.NASL
    descriptionSecurity 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.
    last seen2020-06-05
    modified2019-01-03
    plugin id120335
    published2019-01-03
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/120335
    titleFedora 28 : tinc (2018-31c2a0b2ea)
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DSA-4312.NASL
    descriptionSeveral 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.
    last seen2020-06-01
    modified2020-06-02
    plugin id117958
    published2018-10-09
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/117958
    titleDebian DSA-4312-1 : tinc - security update