CVE-2022-22153: SRX Series and MX Series with SPC3: A high percentage of fragments might lead to high latency or packet drops

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-01-19 · updated 2026-06-17
Weakness: CWE-407

Description

An Insufficient Algorithmic Complexity combined with an Allocation of Resources Without Limits or Throttling vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX Series and MX Series with SPC3 allows an unauthenticated network attacker to cause latency in transit packet processing and even packet loss. If transit traffic includes a significant percentage (> 5%) of fragmented packets which need to be reassembled, high latency or packet drops might be observed. This issue affects Juniper Networks Junos OS on SRX Series, MX Series with SPC3: All versions prior to 18.2R3; 18.3 versions prior to 18.3R3; 18.4 versions prior to 18.4R2-S9, 18.4R3; 19.1 versions prior to 19.1R2; 19.2 versions prior to 19.2R1-S1, 19.2R2.

Affected products

Juniper Junos OS: before 18.2; 18.2, 18.2-r, 18.2-r1, 18.2-r1-s2, 18.2-r1-s3, 18.2-r1-s4 (+52) — fixed in 18.2

How to fix

Upgrade to a fixed version: Juniper Junos OS 18.2. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2022-22153 or the next vulnerability affects your stack