Vulnerabilities > CVE-2018-14055 - Improper Input Validation vulnerability in multiple products
Attack vector
NETWORK Attack complexity
LOW Privileges required
LOW Confidentiality impact
NONE Integrity impact
HIGH Availability impact
NONE Summary
ZNC before 1.7.1-rc1 does not properly validate untrusted lines coming from the network, allowing a non-admin user to escalate his privilege and inject rogue values into znc.conf.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Buffer Overflow via Environment Variables This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
- Server Side Include (SSI) Injection An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
- Cross Zone Scripting An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
- Cross Site Scripting through Log Files An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
- Command Line Execution through SQL Injection An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.
Nessus
NASL family SuSE Local Security Checks NASL id OPENSUSE-2019-571.NASL description This update for znc fixes the following issues : - Update to version 1.7.1 - CVE-2018-14055: non-admin user could gain admin privileges and shell access by injecting values into znc.conf (bnc#1101281) - CVE-2018-14056: path traversal in HTTP handler via ../ in a web skin name. (bnc#1101280) - Update to version 1.7.0 - Make ZNC UI translateable to different languages - Configs written before ZNC 0.206 can last seen 2020-05-31 modified 2019-03-27 plugin id 123248 published 2019-03-27 reporter This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/123248 title openSUSE Security Update : znc (openSUSE-2019-571) NASL family FreeBSD Local Security Checks NASL id FREEBSD_PKG_C6D1A8A68A9111E8BE4D005056925DB4.NASL description Mitre reports : ZNC before 1.7.1-rc1 does not properly validate untrusted lines coming from the network, allowing a non-admin user to escalate his privilege and inject rogue values into znc.conf. ZNC before 1.7.1-rc1 is prone to a path traversal flaw via ../ in a web skin name to access files outside of the intended skins directories. last seen 2020-06-01 modified 2020-06-02 plugin id 111180 published 2018-07-20 reporter This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/111180 title FreeBSD : znc -- multiple vulnerabilities (c6d1a8a6-8a91-11e8-be4d-005056925db4) NASL family Debian Local Security Checks NASL id DEBIAN_DLA-1427.NASL description It was discovered that there were two issues in znc, a modular IRC bouncer : - There was insufficient validation of lines coming from the network allowing a non-admin user to escalate his privilege and inject rogue values into znc.conf. (CVE-2018-14055) - A path traversal vulnerability (via last seen 2020-06-01 modified 2020-06-02 plugin id 111085 published 2018-07-16 reporter This script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/111085 title Debian DLA-1427-1 : znc security update NASL family Debian Local Security Checks NASL id DEBIAN_DSA-4252.NASL description Jeriko One discovered two vulnerabilities in the ZNC IRC bouncer which could result in privilege escalation or denial of service. last seen 2020-06-01 modified 2020-06-02 plugin id 111175 published 2018-07-20 reporter This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/111175 title Debian DSA-4252-1 : znc - security update NASL family SuSE Local Security Checks NASL id OPENSUSE-2018-819.NASL description This update for znc fixes the following issues : - Update to version 1.7.1 - CVE-2018-14055: non-admin user could gain admin privileges and shell access by injecting values into znc.conf (bnc#1101281) - CVE-2018-14056: path traversal in HTTP handler via ../ in a web skin name. (bnc#1101280) - Update to version 1.7.0 - Make ZNC UI translateable to different languages - Configs written before ZNC 0.206 can last seen 2020-06-05 modified 2018-08-08 plugin id 111584 published 2018-08-08 reporter This script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/111584 title openSUSE Security Update : znc (openSUSE-2018-819) NASL family Gentoo Local Security Checks NASL id GENTOO_GLSA-201807-03.NASL description The remote host is affected by the vulnerability described in GLSA-201807-03 (ZNC:Multiple Vulnerabilities) Multiple vulnerabilities have been discovered in ZNC. Please review the CVE identifiers referenced below for details. Impact : A remote attacker could read arbitary files and esclate privileges. Workaround : There is no known workaround at this time. last seen 2020-06-01 modified 2020-06-02 plugin id 111411 published 2018-07-30 reporter This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/111411 title GLSA-201807-03 : ZNC:Multiple Vulnerabilities
References
- https://github.com/znc/znc/commit/a7bfbd93812950b7444841431e8e297e62cb524e
- https://github.com/znc/znc/commit/a7bfbd93812950b7444841431e8e297e62cb524e
- https://github.com/znc/znc/commit/d22fef8620cdd87490754f607e7153979731c69d
- https://github.com/znc/znc/commit/d22fef8620cdd87490754f607e7153979731c69d
- https://security.gentoo.org/glsa/201807-03
- https://security.gentoo.org/glsa/201807-03
- https://www.debian.org/security/2018/dsa-4252
- https://www.debian.org/security/2018/dsa-4252