TI-2020-03046 Aliases CVE-2020-3500 GHSA-5vvg-4mgq-x55f

Cisco StarOS IPv6 Denial of Service Vulnerability

MEDIUM 41CWE-119Published 2020-08-17 · Updated 2024-11-13

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-119 and the CVSS impact.

Summary

A vulnerability in the IPv6 implementation of Cisco StarOS could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient validation of incoming IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet to an affected device with the goal of reaching the vulnerable section of the input buffer. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. This vulnerability is specific to IPv6 traffic. IPv4 traffic is not affected.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.01618 76th 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 ASR 5000 Series Software	all versions	—	No fix listed	CNA

Cisco ASR 5000 Series Software VendorCisco Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 4

CPE	Versions	Role	Vendor
cpe:2.3:o:cisco:staros::::::::	before 21.18.3	Vulnerable	Cisco
cpe:2.3:a:cisco:virtualized_packet_core-single_instance:-:::::::*	not specified by NVD	Running on	Cisco
cpe:2.3:h:cisco:asr_5500:-:::::::*	not specified by NVD	Running on	Cisco
cpe:2.3:h:cisco:asr_5700:-:::::::*	not specified by NVD	Running on	Cisco

cpe:2.3:o:cisco:staros:*:*:*:*:*:*:*:* Versions before 21.18.3 Vulnerable ·Cisco
cpe:2.3:a:cisco:virtualized_packet_core-single_instance:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
cpe:2.3:h:cisco:asr_5500:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
cpe:2.3:h:cisco:asr_5700:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2020-3500
2026-10-03 Alias added: GHSA-5vvg-4mgq-x55f

References

Advisory 1

20200805 Cisco StarOS IPv6 Denial of Service Vulnerability

TI-2025-23504 Erlang/OTP SSH Vulnerable to Pre-Authentication RCE KEVCVSS 3.1CRITICAL 10.0
TI-2019-01491 Cisco StarOS Denial of Service Vulnerability CVSS 3.0HIGH 8.6
TI-2018-00328 Improper input validation in Cisco StarOS unknown CVSS 3.0HIGH 8.6
TI-2021-01080 Cisco StarOS IPv4 Denial of Service Vulnerability CVSS 3.1HIGH 8.6
TI-2018-00201 Improper input validation in Cisco StarOS CVSS 3.1HIGH 7.5
TI-2021-01105 Cisco StarOS Denial of Service Vulnerability CVSS 3.1HIGH 7.5

See all 24 →

Sources

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