CVE-2023-22409 — An Unchecked Input for Loop Condition vulnerability in a NAT library of Juniper

An Unchecked Input for Loop Condition vulnerability in a NAT library of Juniper Networks Junos OS allows a local authenticated attacker with low privileges to cause a Denial of Service (DoS). When an inconsistent "deterministic NAT" configuration is present on an SRX, o

01What is this vulnerability?

An Unchecked Input for Loop Condition vulnerability in a NAT library of Juniper Networks Junos OS allows a local authenticated attacker with low privileges to cause a Denial of Service (DoS). When an inconsistent "deterministic NAT" configuration is present on an SRX, or MX with SPC3 and then a specific CLI command is issued the SPC will crash and restart. Repeated execution of this command will…

02Affected products

Vendor	Product	Versions
Juniper Networks	Junos OS	unspecified, 20.1R1, 20.2, 20.3, 20.4, 21.1, 21.2, 21.3, 21.4, 22.1, 22.2

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-01-12T00:00:00.000Z
• Last modified: 2025-04-07T15:33:24.631Z

09References

• kb.juniper.net — https://kb.juniper.net/JSA70205