Vulnerability · Published Apr 22, 2021 · Assigned by juniper

CVE-2021-0264Junos OS and Junos OS Evolved: MX Series with MPC10/MPC11, PTX10003, PTX10008: Line card may crash and restart when traffic is hitting a firewall filter having a term with syslog action configured

Medium 5.9

In plain English

A medium-severity security flaw in Junos OS from Juniper Networks. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 62% of all known vulnerabilities).

Severity (CVSS 3.1)5.9Medium
Exploit odds (30 days)1.0%top 37.6% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

A vulnerability in the processing of traffic matching a firewall filter containing a syslog action in Juniper Networks Junos OS on MX Series with MPC10/MPC11 cards installed, PTX10003 and PTX10008 Series devices, will cause the line card to crash and restart, creating a Denial of Service (DoS). Continued receipt and processing of packets matching the firewall filter can create a sustained Denial of Service (DoS) condition. When traffic hits the firewall filter, configured on lo0 or any physical interface on the line card, containing a term with a syslog action (e.g. 'term <name> then syslog'), the affected line card will crash and restart, impacting traffic processing through the ports of the line card. This issue only affects MX Series routers with MPC10 or MPC11 line cards, and PTX10003 or PTX10008 Series packet transport routers. No other platforms or models of line cards are affected by this issue. Note: This issue has also been identified and described in technical service bulletin TSB17931 (login required). This issue affects: Juniper Networks Junos OS on MX Series: 19.3 versions prior to 19.3R3-S2; 19.4 versions prior to 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 20.3R3; 20.4 versions prior to 20.4R2. Juniper Networks Junos OS Evolved on PTX10003, PTX10008: All versions prior to 20.4R2-EVO. This issue does not affect Juniper Networks Junos OS versions prior to 19.3R1.

Affected products (as reported)

VendorProductVersions
Juniper Networks Junos OS see references
Juniper Networks Junos OS 19.3 – before 19.3R3-S219.4 – before 19.4R3-S220.1 – before 20.1R320.2 – before 20.2R2-S2, 20.2R320.3 – before 20.3R320.4 – before 20.4R2
Juniper Networks Junos OS Evolved unspecified – before 20.4R2-EVO

Weakness: CWE-703 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References