Juniper Junos OS on ACX IPv6 Firewall Filter unexpected data type

Summaryinfo

A vulnerability described as critical has been identified in Juniper Junos OS on ACX. The affected element is an unknown function of the component IPv6 Firewall Filter. Executing a manipulation can lead to improper handling of unexpected data type. This vulnerability is registered as CVE-2023-28961. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Juniper Junos OS on ACX (Router Operating System) (unknown version) and classified as critical. This vulnerability affects an unknown code block of the component IPv6 Firewall Filter. The manipulation with an unknown input leads to a improper handling of unexpected data type vulnerability. The CWE definition for the vulnerability is CWE-241. The product does not handle or incorrectly handles when a particular element is not the expected type, e.g. it expects a digit (0-9) but is provided with a letter (A-Z). As an impact it is known to affect integrity, and availability. CVE summarizes:

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.

The weakness was published 04/18/2023 as JSA70586. The advisory is available at supportportal.juniper.net. This vulnerability was named CVE-2023-28961 since 03/29/2023. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 12/07/2025).

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2023-32579). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Router Operating System

Vendor

• Juniper

Name

• Junos OS

License

• commercial

Website

• Vendor: https://www.juniper.net/

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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