Vulnerabilities > CVE-2018-14056 - Path Traversal vulnerability in multiple products
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
LOW Integrity impact
NONE Availability impact
NONE Summary
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.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Relative Path Traversal An attacker exploits a weakness in input validation on the target by supplying a specially constructed path utilizing dot and slash characters for the purpose of obtaining access to arbitrary files or resources. An attacker modifies a known path on the target in order to reach material that is not available through intended channels. These attacks normally involve adding additional path separators (/ or \) and/or dots (.), or encodings thereof, in various combinations in order to reach parent directories or entirely separate trees of the target's directory structure.
- Directory Traversal An attacker with access to file system resources, either directly or via application logic, will use various file path specification or navigation mechanisms such as ".." in path strings and absolute paths to extend their range of access to inappropriate areas of the file system. The attacker attempts to either explore the file system for recon purposes or access directories and files that are intended to be restricted from their access. Exploring the file system can be achieved through constructing paths presented to directory listing programs, such as "ls" and 'dir', or through specially crafted programs that attempt to explore the file system. The attacker engaging in this type of activity is searching for information that can be used later in a more exploitive attack. Access to restricted directories or files can be achieved through modification of path references utilized by system applications.
- File System Function Injection, Content Based An attack of this type exploits the host's trust in executing remote content including binary files. The files are poisoned with a malicious payload (targeting the file systems accessible by the target software) by the attacker and may be passed through standard channels such as via email, and standard web content like PDF and multimedia files. The attacker exploits known vulnerabilities or handling routines in the target processes. Vulnerabilities of this type have been found in a wide variety of commercial applications from Microsoft Office to Adobe Acrobat and Apple Safari web browser. When the attacker knows the standard handling routines and can identify vulnerabilities and entry points they can be exploited by otherwise seemingly normal content. Once the attack is executed, the attackers' program can access relative directories such as C:\Program Files or other standard system directories to launch further attacks. In a worst case scenario, these programs are combined with other propagation logic and work as a virus.
- Using Slashes and URL Encoding Combined to Bypass Validation Logic This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple way of encoding an URL and abuse the interpretation of the URL. An URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
- Manipulating Input to File System Calls An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
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/a4a5aeeb17d32937d8c7d743dae9a4cc755ce773
- https://github.com/znc/znc/commit/a4a5aeeb17d32937d8c7d743dae9a4cc755ce773
- 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