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2021-04 Security Bulletin: Junos OS and Junos OS Evolved: An attacker sending a specific crafted BGP update message will crash RPD (CVE-2021-0250)



Article ID: JSA11143 SECURITY_ADVISORIES Last Updated: 14 Apr 2021Version: 1.0
Product Affected:
This issue affects Junos OS , 17.4, 18.1, 18.2, 18.3, 18.4, 19.1, 19.2. This issue affects Junos OS Evolved 19.2-EVO.

In segment routing traffic engineering (SRTE) environments where the BGP Monitoring Protocol (BMP) feature is enable, a vulnerability in the Routing Protocol Daemon (RPD) process of Juniper Networks Junos OS allows an attacker to send a specific crafted BGP update message causing the RPD service to core, creating a Denial of Service (DoS) Condition.

Continued receipt and processing of this update message will create a sustained Denial of Service (DoS) condition.

This issue affects IPv4 and IPv6 environments.

This issue affects:

Juniper Networks Junos OS:

  • 17.4 versions 17.4R1 and above prior to 17.4R2-S6, 17.4R3;
  • 18.1 versions prior to 18.1R3-S7;
  • 18.2 versions prior to 18.2R2-S6, 18.2R3-S3;
  • 18.3 versions prior to 18.3R1-S7, 18.3R2-S3, 18.3R3;
  • 18.4 versions prior to 18.4R1-S5, 18.4R2-S3, 18.4R3;
  • 19.1 versions prior to 19.1R1-S4, 19.1R2;
  • 19.2 versions prior to 19.2R1-S3, 19.2R2,
  • This issue does not affect Junos OS releases prior to 17.4R1.

This issue affects:

  • Juniper Networks Junos OS Evolved 19.2-EVO versions prior to 19.2R2-EVO.

This issue requires a SRTE topology using BGP with BGP Monitoring Protocol to be enabled.

For example:

[routing-options bmp]

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-2021-0250.


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

Junos OS: 17.4R2-S6, 17.4R3, 18.1R3-S7, 18.2R2-S6, 18.2R3-S3, 18.3R1-S7, 18.3R2-S3, 18.3R3, 18.4R1-S5, 18.4R2-S3, 18.4R3, 19.1R1-S4, 19.1R2, 19.2R1-S3, 19.2R2, 19.3R1, and all subsequent releases.

Junos OS Evolved: 19.2R2-EVO, and all subsequent releases.

This issue is being tracked as 1442721.

Disable BGP monitoring protocol until a fix can be applied.
Software releases or updates are available for download at
Modification History:
2021-04-14: 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:
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."

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