Juniper Networks has upgraded the ​OpenSSL library included in Juniper Networks Junos OS and Junos OS Evolved to fix a specific vulnerability.

CVE-2022-0778: The BN_mod_sqrt() function, which computes a modular square root, contains a bug that can cause it to loop forever for non-prime moduli. Internally this function is used when parsing certificates that contain elliptic curve public keys in compressed form or explicit elliptic curve parameters with a base point encoded in compressed form. It is possible to trigger the infinite loop by crafting a certificate that has invalid explicit curve parameters. Since certificate parsing happens prior to verification of the certificate signature, any process that parses an externally supplied certificate may thus be subject to a denial of service attack. The infinite loop can also be reached when parsing crafted private keys as they can contain explicit elliptic curve parameters. Thus vulnerable situations include: - TLS clients consuming server certificates - TLS servers consuming client certificates - Hosting providers taking certificates or private keys from customers - Certificate authorities parsing certification requests from subscribers - Anything else which parses ASN.1 elliptic curve parameters Also any other applications that use the BN_mod_sqrt() where the attacker can control the parameter values are vulnerable to this DoS issue. In the OpenSSL 1.0.2 version the public key is not parsed during initial parsing of the certificate which makes it slightly harder to trigger the infinite loop. However any operation which requires the public key from the certificate will trigger the infinite loop. In particular the attacker can use a self-signed certificate to trigger the loop during verification of the certificate signature.

This issue affects:

Juniper Networks Junos OS Evolved

• All versions prior to 20.4R2-EVO;
• 21.1 versions prior to 21.1R2-EVO;
• 21.2 version 21.2R1 and later versions;
• 21.3 versions prior to 21.3R2-EVO.

Juniper Networks Junos OS

• All versions prior to 19.1R3-S9;
• 19.2 version 19.2R1 and later versions;
• 19.3 versions prior to 19.3R3-S6;
• 19.4 versions prior to 19.4R2-S7, 19.4R3-S9;
• 20.1 versions prior to 20.1R3-S4;
• 20.2 versions prior to 20.2R3-S5;
• 20.3 versions prior to 20.3R3-S4;
• 20.4 versions prior to 20.4R3-S4;
• 21.1 versions prior to 21.1R3-S3;
• 21.2 versions prior to 21.2R3-S1;
• 21.3 versions prior to 21.3R3-S1;
• 21.4 versions prior to 21.4R2;
• 22.1 versions prior to 22.1R2.

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

This issue was discovered during external security research.

This issue has been assigned CVE-2022-0778.

The following software releases have been updated to resolve this specific issue:

Junos OS Evolved 20.4R2-EVO, 21.1R2-EVO, 21.3R2-EVO, 21.4R1-EVO, and all subsequent releases.

Junos OS: 19.1R3-S9, 19.3R3-S6, 19.4R2-S7, 19.4R3-S9, 20.1R3-S4, 20.2R3-S5, 20.3R3-S4, 20.4R3-S4, 21.1R3-S3, 21.2R3-S1, 21.3R3-S1, 21.4R2, 22.1R2, 22.2R1, and all subsequent releases.

This issue is being tracked as 1655643, 1653860 and 1653861.

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

There are no known workarounds for this issue.

To reduce the risk of exploitation of this issue, use access lists or firewall filters to limit access to only trusted networks, hosts and users.

• 2023-01-11: 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-2022-0778 at cve.mitre.org