CVE-2023-28961

CVE-2023-28961 is a medium-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 5.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-241.

Key facts

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.

Frequently asked questions

What is CVE-2023-28961?
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.
How severe is CVE-2023-28961?
CVE-2023-28961 has a CVSS 3.x base score of 5.8, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2023-28961 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-28961?
CVE-2023-28961 primarily affects Juniper Junos. In total, 64 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-28961?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-28961 published?
CVE-2023-28961 was published on 2023-04-17 and last updated on 2026-06-17.

References

Affected products (64)

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