TI-2019-01531 Aliases CVE-2019-1910 GHSA-25g3-p7c7-27pp

Cisco IOS XR Software Intermediate System to Intermediate System Denial of Service Vulnerability

LOW 33CWE-20Published 2019-08-07 · Updated 2024-11-21

Key facts

Attack vector: Adjacent network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

A vulnerability in the implementation of the Intermediate System–to–Intermediate System (IS–IS) routing protocol functionality in Cisco IOS XR Software could allow an unauthenticated attacker who is in the same IS–IS area to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of crafted IS–IS link-state protocol data units (PDUs). An attacker could exploit this vulnerability by sending a crafted link-state PDU to an affected system to be processed. A successful exploit could allow the attacker to cause all routers within the IS–IS area to unexpectedly restart the IS–IS process, resulting in a DoS condition. This vulnerability affects Cisco devices if they are running a vulnerable release of Cisco IOS XR Software earlier than Release 6.6.3 and are configured with the IS–IS routing protocol. Cisco has confirmed that this vulnerability affects both Cisco IOS XR 32-bit Software and Cisco IOS XR 64-bit Software.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00447 39th percentileScored 2026-11-07

Fix Fixed Cisco IOS XR Software (Cisco): 6.6.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Cisco	Cisco IOS XR Software	before 6.6.3	6.6.3	Patch available	CNA

Cisco IOS XR Software VendorCisco Affected before 6.6.3 Fixed in 6.6.3 Patch available CNA

CPE configurations NVD · 2

CPE	Versions	Role	Vendor
cpe:2.3:o:cisco:ios_xr::::::::	before 6.6.3	Vulnerable	Cisco
cpe:2.3:a:cisco:carrier_routing_system:7.0.1:::::::*	7.0.1	Vulnerable	Cisco

cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:* Versions before 6.6.3 Vulnerable ·Cisco
cpe:2.3:a:cisco:carrier_routing_system:7.0.1:*:*:*:*:*:*:* Versions 7.0.1 Vulnerable ·Cisco

Remediation

Fix · CNA Cisco IOS XR Software (Cisco) Fixed in 6.6.3

Timeline

2026-10-02 Threatist record created from CVE-2019-1910
2026-10-03 Alias added: GHSA-25g3-p7c7-27pp

References

Advisory 1

20190807 Cisco IOS XR Software Intermediate System System Denial of Service Vulnerability

TI-2018-00106 Memory corruption in Cisco IOS XR CVSS 3.0HIGH 8.6
TI-2015-00573 Cisco IOS XR 5.0.1 and 5.2.1 on Network Convergence System (NCS) 6000 devices and 5.1.3… CVSS 2.0HIGH 7.1
TI-2019-01538 Cisco IOS XR Software Intermediate System–to–Intermediate System Denial of Service Vulnerability CVSS 3.1HIGH 7.4
TI-2012-01192 Cisco Carrier Routing System (CRS) 3.9, 4.0, and 4.1 allows remote attackers to bypass… CVSS 3.1MEDIUM 5.8
TI-2013-00961 Cisco Carrier Routing System (CRS) allows remote attackers to cause a denial of service… CVSS 2.0MEDIUM 5.0
TI-2011-02911 Cisco Carrier Routing System 3.9.1 allows remote attackers to cause a denial of service… CVSS 2.0MEDIUM 5.0

See all 7 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences