CVE-2023-28961

Junos OS: ACX Series: IPv6 firewall filter is not installed in PFE when "from next-header ah" is used

Description

An Improper Handling of Unexpected Data Type vulnerability in IPv6 firewall filter processing of Juniper Networks Junos OS on the ACX Series devices will prevent a firewall filter with the term 'from next-header ah' from being properly installed in the packet forwarding engine (PFE). There is no immediate indication of an incomplete firewall filter commit shown at the CLI, which could allow an attacker to send valid packets to or through the device that were explicitly intended to be dropped. An indication that the filter was not installed can be identified with the following logs: fpc0 ACX_DFW_CFG_FAILED: ACX Error (dfw):dnx_dfw_rule_prepare : Config failed: Unsupported Ip-protocol 51 in the filter lo0.0-inet6-i fpc0 ACX_DFW_CFG_FAILED: ACX Error (dfw):dnx_dfw_rule_prepare : Please detach the filter, remove unsupported match and re-attach fpc0 ACX_DFW_CFG_FAILED: ACX Error (dfw):dnx_dfw_process_rule : Status:104 dnx_dfw_rule_prepare failed fpc0 ACX_DFW_CFG_FAILED: ACX Error (dfw):dnx_dfw_process_filter : Status:104 dnx_dfw_process_rule failed fpc0 ACX_DFW_CFG_FAILED: ACX Error (dfw):dnx_dfw_update_filter_in_hw : Status:104 Could not process filter(lo0.0-inet6-i) for rule expansion Unsupported match, action present. fpc0 ACX_DFW_CFG_FAILED: ACX Error (dfw):dnx_dfw_create_hw_instance : Status:104 Could not program dfw(lo0.0-inet6-i) type(IFP_DFLT_INET6_Lo0_FILTER)! [104] fpc0 ACX_DFW_CFG_FAILED: ACX Error (dfw):dnx_dfw_bind_shim : [104] Could not create dfw(lo0.0-inet6-i) type(IFP_DFLT_INET6_Lo0_FILTER) fpc0 ACX_DFW_CFG_FAILED: ACX Error (dfw):dnx_dfw_update_resolve : [100] Failed to bind filter(3) to bind point fpc0 ACX_DFW_CFG_FAILED: ACX Error (dfw):dnx_dfw_change_end : dnx_dfw_update_resolve (resolve type) failed This issue affects Juniper Networks Junos OS on ACX Series: All versions prior to 20.2R3-S7; 20.4 versions prior to 20.4R3-S4; 21.1 versions prior to 21.1R3-S3; 21.2 versions prior to 21.2R3-S4; 21.3 versions prior to 21.3R3; 21.4 versions prior to 21.4R3; 22.1 versions prior to 22.1R2.

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue: 20.2R3-S7, 20.4R3-S4, 21.1R3-S3, 21.2R3-S4, 21.3R3, 21.4R3, 22.1R2, 22.2R1, and all subsequent releases.

Workaround:

  • There are no known workarounds for this issue.

Category

5.8
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.15%
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2023-28961?
CVE-2023-28961 has been scored as a medium severity vulnerability.
How to fix CVE-2023-28961?
To fix CVE-2023-28961: The following software releases have been updated to resolve this specific issue: 20.2R3-S7, 20.4R3-S4, 21.1R3-S3, 21.2R3-S4, 21.3R3, 21.4R3, 22.1R2, 22.2R1, and all subsequent releases.
Is CVE-2023-28961 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-28961 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-28961?
CVE-2023-28961 affects Juniper Networks Junos OS.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.