CVE-2023-22411 — An Out-of-Bounds Write vulnerability in Flow Processing Daemon (flowd) of Junipe

An Out-of-Bounds Write vulnerability in Flow Processing Daemon (flowd) of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause Denial of Service (DoS). On SRX Series devices using Unified Policies with IPv6, when a specific IPv6 packet goes through

01What is this vulnerability?

An Out-of-Bounds Write vulnerability in Flow Processing Daemon (flowd) of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause Denial of Service (DoS). On SRX Series devices using Unified Policies with IPv6, when a specific IPv6 packet goes through a dynamic-application filter which will generate an ICMP deny message, the flowd core is observed and the PFE is…

02Affected products

Vendor	Product	Versions
Juniper Networks	Junos OS	19.2, 19.3, 19.4, 20.2, 20.3, 20.4, 21.1, 21.2, 21.3, 21.4

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: 2025-04-07T15:32:39.451Z

09References

• kb.juniper.net — https://kb.juniper.net/JSA70207