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Product Affected

This issue affects Junos OS All versions before 22.2R3-S6, 22.4, 23.2, 23.4, 24.2. Affected platforms: MX240, MX480, MX960, with SPC3.

Severity

High

Severity Assessment (CVSS) Score

CVSS: v3.1: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVSS: v4.0: 8.7 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/V:C/RE:M/U:Amber)

Problem

An Improper Input Validation vulnerability in the syslog stream TCP transport of Juniper Networks Junos OS on MX240, MX480, and MX960 devices with MX-SPC3 Security Services Card allows an unauthenticated, network-based attacker, to send specific spoofed packets to cause a CPU Denial of Service (DoS) to the MX-SPC3 SPUs.

Continued receipt and processing of these specific packets will sustain the DoS condition.

An indicator of compromise will indicate the SPC3 SPUs utilization has spiked.
For example:
user@device> show services service-sets summary

Service sets                                                                                          CPU
  Interface       configured     Bytes used           Session bytes used       Policy bytes used      utilization
  "interface"       1            "bytes" (percent%)   "sessions" ("percent"%)  "bytes" ("percent"%)   99.97 % OVLD  <<<<<< look for high CPU usage

This issue affects Junos OS:

All versions before 22.2R3-S6,
from 22.4 before 22.4R3-S4,
from 23.2 before 23.2R2-S3,
from 23.4 before 23.4R2-S4,
from 24.2 before 24.2R1-S2, 24.2R2

Required configuration for exposure:

[ services service-set "service-set-name" syslog stream "stream-name" host "syslog-server-ip-address-or-hostname" ]
[ services service-set "service-set-name" syslog stream "stream-name" host port "syslog-server-port" ]
[ services service-set "service-set-name" syslog stream "stream-name" transport protocol tcp ]
[ services service-set "service-set-name" syslog stream "stream-name" source-address "syslog-collector-ip-address" ]

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

This issue was seen during production usage.

Solution

The following software releases have been updated to resolve this specific issue: Junos OS: 22.2R3-S6, 22.4R3-S4, 23.2R2-S3, 23.4R2-S4, 24.2R1-S2, 24.2R2, 24.4R1, and all subsequent releases.

This issue is being tracked as 1823932 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).

Workaround

There are no known workarounds for this issue.

Severity Assessment

Information for how Juniper Networks uses CVSS can be found at KB 16446 [juniper.net] "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Modification History