TI-2019-09460 Aliases CVE-2019-12664 GHSA-qf56-4c48-p66f

Cisco IOS XE Software ISDN Data Leak Vulnerability

LOW 36CWE-200Published 2019-09-25 · Updated 2024-11-21

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Information disclosure, Security bypass
Confidentiality · integrity · availability: None · High · None
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-200 and CWE-287.

Summary

A vulnerability in the Dialer interface feature for ISDN connections in Cisco IOS XE Software for Cisco 4000 Series Integrated Services Routers (ISRs) could allow an unauthenticated, adjacent attacker to pass IPv4 traffic through an ISDN channel prior to successful PPP authentication. The vulnerability is due to insufficient validation of the state of the PPP IP Control Protocol (IPCP). An attacker could exploit this vulnerability by making an ISDN call to an affected device and sending traffic through the ISDN channel prior to successful PPP authentication. Alternatively, an unauthenticated, remote attacker could exploit this vulnerability by sending traffic through an affected device that is configured to exit via an ISDN connection for which both the Dialer interface and the Basic Rate Interface (BRI) have been configured, but the Challenge Handshake Authentication Protocol (CHAP) password for PPP does not match the remote end. A successful exploit could allow the attacker to pass IPv4 traffic through an unauthenticated ISDN connection for a few seconds, from initial ISDN call setup until PPP authentication fails.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.01425 73rd percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

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 XE Software	all versions	—	No fix listed	CNA

Cisco IOS XE Software VendorCisco Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 4

CPE	Versions	Role	Vendor
cpe:2.3:o:cisco:ios_xe:16.6.4:::::::*	16.6.4	Vulnerable	Cisco
cpe:2.3:h:cisco:4321_integrated_services_router:-:::::::*	not specified by NVD	Running on	Cisco
cpe:2.3:h:cisco:4331_integrated_services_router:-:::::::*	not specified by NVD	Running on	Cisco
cpe:2.3:h:cisco:4351_integrated_services_router:-:::::::*	not specified by NVD	Running on	Cisco

cpe:2.3:o:cisco:ios_xe:16.6.4:*:*:*:*:*:*:* Versions 16.6.4 Vulnerable ·Cisco
cpe:2.3:h:cisco:4321_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
cpe:2.3:h:cisco:4331_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
cpe:2.3:h:cisco:4351_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco

Remediation

No fixed version listed by the sources yet.

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2019-09-25
Cisco IOS XE Software n/a
4 records Highest priority Priority MEDIUM 2 MEDIUM, 2 LOW
Other records, highest priority first
- TI-2019-09449 Cisco IOS XE Software Raw Socket Transport Denial of Service VulnerabilityPriority MEDIUM 43
- TI-2019-09459 Cisco IOS XE Software TrustSec Protected Access Credential Provisioning Denial of Service VulnerabilityPriority MEDIUM 41
- TI-2019-09457 Cisco IOS XE Software Virtualization Manager CLI Command Injection VulnerabilityPriority LOW 32
Show all 4 records →

Timeline

2026-10-02 Threatist record created from CVE-2019-12664
2026-10-03 Alias added: GHSA-qf56-4c48-p66f

References

Advisory 1

20190925 Cisco IOS XE Software ISDN Data Leak Vulnerability

TI-2023-06904 Cisco is providing an update for the ongoing investigation into observed exploitation of… KEVCVSS 3.1CRITICAL 10.0
TI-2018-00122 Memory corruption in Cisco IOS and IOS XE KEVCVSS 3.1CRITICAL 9.8
TI-2017-02977 Improper input validation in Cisco IOS and IOS XE Software KEVCVSS 3.1CRITICAL 9.8
TI-2018-00135 Memory corruption in Cisco IOS, IOS XE, and IOS XR KEVCVSS 3.1HIGH 8.8
TI-2017-04498 Memory corruption in Cisco IOS KEVCVSS 3.1HIGH 8.8
TI-2017-04497 Memory corruption in Cisco IOS XE Software KEVCVSS 3.1HIGH 8.8

See all 561 →

Sources

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