Support Support Downloads Knowledge Base Juniper Support Portal Community

Knowledge Base

Search our Knowledge Base sites to find answers to your questions.

Ask All Knowledge Base Sites All Knowledge Base Sites JunosE Defect (KA)Knowledge BaseSecurity AdvisoriesTechnical BulletinsTechnotes Sign in to display secure content and recently viewed articles

2021-01 Security Bulletin: Junos OS: SRX Series: A logic error in BIND can be used to trigger a Denial of Service (DoS) (CVE-2020-8617)

0

0

Article ID: JSA11091 SECURITY_ADVISORIES Last Updated: 13 Jan 2021Version: 1.0
Product Affected:
This issue affects Junos OS 12.3X48, 15.1X49, 17.3, 17.4, 18.1, 18.2, 18.3, 18.4, 19.1, 19.2, 19.3, 19.4, 20.1, 20.2. Affected platforms: SRX Series.
Problem:

A vulnerability in BIND code, used in Juniper Networks Junos OS on SRX Series devices, which checks the validity of messages containing TSIG resource records can be exploited by an attacker to trigger an assertion failure in tsig.c, resulting in a Denial of Service (DoS).

Using a specially-crafted message, an attacker may potentially cause a BIND server to reach an inconsistent state if the attacker knows (or successfully guesses) the name of a TSIG key used by the server. Since BIND, by default, configures a local session key even on servers whose configuration does not otherwise make use of it, almost all current BIND servers are vulnerable. In vulnerable releases of BIND, the server is missing an assertion check in tsig.c to detect this inconsistent state, and would continue operating in an inconsistent state, with potentially harmful results.

This issue only affect SRX Series devices, which is the only platform that ships with BIND software. No other products or platforms are affected by this vulnerability.

This issue affects Juniper Networks Junos OS on SRX Series:

  • 12.3X48 versions prior to 12.3X48-D105;
  • 15.1X49 versions prior to 15.1X49-D230;
  • 17.3 versions prior to 17.3R3-S10;
  • 17.4 versions prior to 17.4R2-S12, 17.4R3-S4;
  • 18.1 versions prior to 18.1R3-S12;
  • 18.2 versions prior to 18.2R2-S8, 18.2R3-S6;
  • 18.3 versions prior to 18.3R3-S4;
  • 18.4 versions prior to 18.4R1-S8, 18.4R2-S7, 18.4R3-S6;
  • 19.1 versions prior to 19.1R1-S6, 19.1R3-S3;
  • 19.2 versions prior to 19.2R1-S6, 19.2R3;
  • 19.3 versions prior to 19.3R2-S5, 19.3R3;
  • 19.4 versions prior to 19.4R2-S2, 19.4R3;
  • 20.1 versions prior to 20.1R2;
  • 20.2 versions prior to 20.2R1-S2, 20.2R2.


An example of the configuration to enable DNS Proxy is shown below:

set system services dns dns-proxy cache www.example.tld inet 10.10.10.10


Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was seen during production usage.

This issue has been assigned CVE-2020-8617.
 

Solution:
The following software releases have been updated to resolve this specific issue: 12.3X48-D105, 15.1X49-D230, 17.3R3-S10, 17.4R2-S12, 17.4R3-S4, 18.1R3-S12, 18.2R2-S8, 18.2R3-S6, 18.3R3-S4, 18.4R1-S8, 18.4R2-S7, 18.4R3-S6, 19.1R1-S6, 19.1R3-S3, 19.2R1-S6, 19.2R3, 19.3R2-S5, 19.3R3, 19.4R2-S2, 19.4R3, 20.1R2, 20.2R1-S2, 20.2R2, 20.3R1, and all subsequent releases.

This issue is being tracked as 1512810.
 
Workaround:
Disable DNS Proxy on SRX Series devices.
 
Implementation:
Software releases or updates are available for download at https://www.juniper.net/support/downloads/.
 
Modification History:
2021-01-13: Initial Publication.

CVSS Score:
7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Severity Level:
High
Severity Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Related Links

Comment on this article > Affected Products Browse the Knowledge Base for more articles related to these product categories. Select a category to begin.

Getting Up and Running with Junos

Getting Up and Running with Junos Security Alerts and Vulnerabilities Product Alerts and Software Release Notices Problem Report (PR) Search Tool EOL Notices and Bulletins JTAC User Guide Customer Care User Guide Pathfinder SRX High Availability Configurator SRX VPN Configurator Training Courses and Videos End User Licence Agreement Global Search