Vulnerabilities > CVE-2017-15093 - Improper Input Validation vulnerability in Powerdns Recursor
Attack vector
NETWORK Attack complexity
HIGH Privileges required
LOW Confidentiality impact
NONE Integrity impact
HIGH Availability impact
NONE Summary
When api-config-dir is set to a non-empty value, which is not the case by default, the API in PowerDNS Recursor 4.x up to and including 4.0.6 and 3.x up to and including 3.7.4 allows an authorized user to update the Recursor's ACL by adding and removing netmasks, and to configure forward zones. It was discovered that the new netmask and IP addresses of forwarded zones were not sufficiently validated, allowing an authenticated user to inject new configuration directives into the Recursor's configuration.
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 Fedora Local Security Checks NASL id FEDORA_2017-608B6F5945.NASL description Update to latest version. Contains security fixes for CVE-2017-15090, CVE-2017-15092, CVE-2017-15093 and CVE-2017-15094 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 seen 2020-06-05 modified 2018-01-15 plugin id 105888 published 2018-01-15 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/105888 title Fedora 27 : pdns-recursor (2017-608b6f5945) NASL family SuSE Local Security Checks NASL id OPENSUSE-2017-1339.NASL description This update for pdns-recursor fixes the following issues : Security issues fixed : - CVE-2017-15090: An issue has been found in the DNSSEC validation component of PowerDNS Recursor, where the signatures might have been accepted as valid even if the signed data was not in bailiwick of the DNSKEY used to sign it. This allows an attacker in position of man-in-the-middle to alter the content of records by issuing a valid signature for the crafted records (boo#1069242). - CVE-2017-15092: An issue has been found in the web interface of PowerDNS Recursor, where the qname of DNS queries was displayed without any escaping, allowing a remote attacker to inject HTML and JavaScript code into the web interface, altering the content (boo#1069242). - CVE-2017-15093: When `api-config-dir` is set to a non-empty value, which is not the case by default, the API allows an authorized user to update the Recursor last seen 2020-06-05 modified 2017-12-14 plugin id 105229 published 2017-12-14 reporter This script is Copyright (C) 2017-2020 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/105229 title openSUSE Security Update : pdns-recursor (openSUSE-2017-1339) NASL family DNS NASL id POWERDNS_RECURSOR_4_0_7_2017-06.NASL description According to its self-reported version number, the version of the PowerDNS Recursor listening on the remote host is prior to to 4.0.7. It is, therefore, affected by a vulnerability where a remote authenticated user can injection additional configuration directives via the API. Note that Nessus has not attempted to exploit these issues but has instead relied only on the application last seen 2020-06-01 modified 2020-06-02 plugin id 106194 published 2018-01-19 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/106194 title PowerDNS Recursor < 4.0.7 API Configuration Injection Vulnerability (CVE-2017-15093) NASL family Fedora Local Security Checks NASL id FEDORA_2017-1585789772.NASL description Update to latest version. Contains security fixes for CVE-2017-15090, CVE-2017-15092, CVE-2017-15093 and CVE-2017-15094 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 seen 2020-06-05 modified 2017-12-13 plugin id 105198 published 2017-12-13 reporter This script is Copyright (C) 2017-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/105198 title Fedora 26 : pdns-recursor (2017-1585789772) NASL family Fedora Local Security Checks NASL id FEDORA_2017-81FE39AD9F.NASL description Update to latest version. Contains security fixes for CVE-2017-15090, CVE-2017-15092, CVE-2017-15093 and CVE-2017-15094 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 seen 2020-06-05 modified 2017-12-13 plugin id 105203 published 2017-12-13 reporter This script is Copyright (C) 2017-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/105203 title Fedora 25 : pdns-recursor (2017-81fe39ad9f)