An Insufficient Verification of Data Authenticity vulnerability in Juniper Networks Junos OS on the SRX Series devices within the BIND library used by DNS proxy allows an attacker to cause the cache to become poisoned with incorrect records which might lead to queries being made to the wrong servers, which might also result in false information being returned to clients.

This issue only affects SRX series devices with DNS proxy enabled.

This issue affects:

Juniper Networks Junos OS on SRX Series:

• All versions prior to 19.3R3-S7;
• 19.4 versions prior to 19.4R2-S8, 19.4R3-S9;
• 20.2 versions prior to 20.2R3-S5;
• 20.3 versions prior to 20.3R3-S5;
• 20.4 versions prior to 20.4R3-S4;
• 21.1 versions prior to 21.1R3-S3;
• 21.2 versions prior to 21.2R3-S2;
• 21.3 versions prior to 21.3R3-S1;
• 21.4 versions prior to 21.4R2-S1, 21.4R3;
• 22.1 versions prior to 22.1R1-S2, 22.1R3;
• 22.2 versions prior to 22.2R1-S1, 22.2R2.

The following minimal configuration is required:

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-2021-25220.
 

The following software releases have been updated to resolve this specific issue: Junos OS 19.4R2-S8, 19.4R3-S9, 20.2R3-S5, 20.3R3-S5, 20.4R3-S4, 21.1R3-S3, 21.2R3-S2, 21.3R3-S1, 21.4R2-S1, 21.4R3, 22.1R1-S2, 22.1R3, 22.2R1-S1, 22.2R2, 22.3R1, and all subsequent releases.

This issue is being tracked as 1656324 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

IMPLEMENTATION:

Software Releases, patches and updates are available at https://support.juniper.net/support/downloads/.

There are no known workarounds for this issue.

To reduce the impact of exploitation, we suggest customers split primary and secondary DNS lookups and assignments between the local Proxy DNS service and centralized/remote DNS servers.

2022-10-12: Initial Publication

• KB16613: Overview of the Juniper Networks SIRT Quarterly Security Bulletin Publication Process [juniper.net]
• KB16765: In which releases are vulnerabilities fixed? [juniper.net]
• KB16446: Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories [juniper.net]
• Report a Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team
• CVE-2021-25220 at cve.mitre.org
• https://kb.isc.org/v1/docs/cve-2021-25220