How severe is CVE-2017-12319?

CVE-2017-12319 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2017-12319 being actively exploited?

Yes. CVE-2017-12319 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2022-03-03, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2017-12319?

CVE-2017-12319 primarily affects Cisco Ios. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-12319?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2017-12319 have an EU (EUVD) identifier?

Yes. CVE-2017-12319 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2017-3892. It is also flagged as exploited in the EUVD (since 2022-03-03).

When was CVE-2017-12319 published?

CVE-2017-12319 was published on 2018-03-27 and last updated on 2026-06-17.

CVE-2017-12319

CVE-2017-12319 is a medium-severity vulnerability in Cisco Ios with a CVSS 3.x base score of 5.9. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2022-03-03). The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 7.1
EPSS exploit prediction: 5% (92nd percentile)
Actively exploited: Yes — listed in CISA KEV (added 2022-03-03)
EU (EUVD) id: EUVD-2017-3892
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2022-03-03)
Weakness: CWE-20
Affected product: Cisco Ios
Published: 2018-03-27
Last modified: 2026-06-17

Description

A vulnerability in the Border Gateway Protocol (BGP) over an Ethernet Virtual Private Network (EVPN) for Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a denial of service (DoS) condition, or potentially corrupt the BGP routing table, which could result in network instability. The vulnerability exists due to changes in the implementation of the BGP MPLS-Based Ethernet VPN RFC (RFC 7432) draft between IOS XE software releases. When the BGP Inclusive Multicast Ethernet Tag Route or BGP EVPN MAC/IP Advertisement Route update packet is received, it could be possible that the IP address length field is miscalculated. An attacker could exploit this vulnerability by sending a crafted BGP packet to an affected device after the BGP session was established. An exploit could allow the attacker to cause the affected device to reload or corrupt the BGP routing table; either outcome would result in a DoS. The vulnerability may be triggered when the router receives a crafted BGP message from a peer on an existing BGP session. This vulnerability affects all releases of Cisco IOS XE Software prior to software release 16.3 that support BGP EVPN configurations. If the device is not configured for EVPN, it is not vulnerable. Cisco Bug IDs: CSCui67191, CSCvg52875.

Frequently asked questions

What is CVE-2017-12319?: A vulnerability in the Border Gateway Protocol (BGP) over an Ethernet Virtual Private Network (EVPN) for Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a denial of service (DoS) condition, or potentially corrupt the BGP routing table, which could result in network instability. The vulnerability exists due to changes in the implementation of the BGP MPLS-Based Ethernet VPN RFC (RFC 7432) draft between IOS XE software releases. When the BGP Inclusive Multicast Ethernet Tag Route or BGP EVPN MAC/IP Advertisement Route update packet is received, it could be possible that the IP address length field is miscalculated. An attacker could exploit this vulnerability by sending a crafted BGP packet to an affected device after the BGP session was established. An exploit could allow the attacker to cause the affected device to reload or corrupt the BGP routing table; either outcome would result in a DoS. The vulnerability may be triggered when the router receives a crafted BGP message from a peer on an existing BGP session. This vulnerability affects all releases of Cisco IOS XE Software prior to software release 16.3 that support BGP EVPN configurations. If the device is not configured for EVPN, it is not vulnerable. Cisco Bug IDs: CSCui67191, CSCvg52875.
How severe is CVE-2017-12319?: CVE-2017-12319 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2017-12319 being actively exploited?: Yes. CVE-2017-12319 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2022-03-03, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2017-12319?: CVE-2017-12319 primarily affects Cisco Ios. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-12319?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2017-12319 have an EU (EUVD) identifier?: Yes. CVE-2017-12319 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2017-3892. It is also flagged as exploited in the EUVD (since 2022-03-03).
When was CVE-2017-12319 published?: CVE-2017-12319 was published on 2018-03-27 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:o:cisco:ios:15.4\(1\)s:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:*:*:*:*:*:*:*:*

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