Junos OS: MX Series, EX9200 Series: FPC may crash upon receipt of specific MPLS packet affecting Trio-based MPCs

Description

A vulnerability in the processing of specific MPLS packets in Juniper Networks Junos OS on MX Series and EX9200 Series devices with Trio-based MPCs (Modular Port Concentrators) may cause FPC to crash and lead to a Denial of Service (DoS) condition. Continued receipt of this packet will sustain the Denial of Service (DoS) condition. This issue only affects MX Series and EX9200 Series with Trio-based PFEs (Packet Forwarding Engines). This issue affects Juniper Networks Junos OS on MX Series, EX9200 Series: 17.3 versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R2-S13, 17.4R3-S5; 18.1 versions prior to 18.1R3-S13; 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R2-S8, 18.4R3-S8; 19.1 versions prior to 19.1R3-S5; 19.2 versions prior to 19.2R3-S2; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R1-S4, 19.4R2-S4, 19.4R3-S2; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R2-S2, 20.2R3; 20.3 versions prior to 20.3R2; 20.4 versions prior to 20.4R2;

Scores

EPSS (exploitation in 30 days)

0.38% · top 68% of all CVEs (7 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.

Weakness

• CWE-754 Improper Check for Unusual or Exceptional Conditions (opens in a new tab)All about CWE-754 and its CVEs

Affected products

• Juniper Networks · Junos OS

  • affected 17.3 – < 17.3R3-S12
  • affected 17.4 – < 17.4R2-S13, 17.4R3-S5
  • affected 18.1 – < 18.1R3-S13
  • affected 18.2 – < 18.2R3-S8
  • affected 18.3 – < 18.3R3-S5
  • affected 18.4 – < 18.4R2-S8, 18.4R3-S8
  • affected 19.1 – < 19.1R3-S5
  • affected 19.2 – < 19.2R3-S2
  • affected 19.3 – < 19.3R2-S6, 19.3R3-S3
  • affected 19.4 – < 19.4R1-S4, 19.4R1-S4, 19.4R2-S4, 19.4R3-S2
  • affected 20.1 – < 20.1R3
  • affected 20.2 – < 20.2R2-S2, 20.2R3
  • affected 20.3 – < 20.3R2
  • affected 20.4 – < 20.4R2

What to do

Solution: The following software releases have been updated to resolve this specific issue: Junos OS 17.3R3-S12, 17.4R2-S13, 17.4R3-S5, 18.1R3-S13, 18.2R3-S8, 18.3R3-S5, 18.4R2-S8, 18.4R3-S8, 19.1R3-S5, 19.2R3-S2, 19.3R2-S6, 19.3R3-S3, 19.4R2-S4, 19.4R3-S2, 20.1R3, 20.2R2-S2, 20.2R3, 20.3R2, 20.4R2, 21.1R1, and all subsequent releases.

Workaround: There are no viable workarounds for this issue.

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

References (1)

• https://kb.juniper.net/JSA11190 (opens in a new tab)x_refsource_CONFIRMx_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2021-0288](https://trackcve.app/badge/CVE-2021-0288.svg)](https://trackcve.app/cve/CVE-2021-0288)

Record last updated 17 Sept 2024, 02:10 UTC.