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TI-2021-01105 Aliases CVE-2021-1378GHSA-qj86-q34h-pf43

Cisco StarOS Denial of Service Vulnerability

Priority MEDIUM 42CWE-400Published · Updated

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-400.

Summary

A vulnerability in the SSH service of the Cisco StarOS operating system could allow an unauthenticated, remote attacker to cause an affected device to stop processing traffic, resulting in a denial of service (DoS) condition. The vulnerability is due to a logic error that may occur under specific traffic conditions. An attacker could exploit this vulnerability by sending a series of crafted packets to an affected device. A successful exploit could allow the attacker to prevent the targeted service from receiving any traffic, which would lead to a DoS condition on the affected device.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01502 74th 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
Yes
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
CiscoCisco ASR 5000 Series Softwareall versions—No fix listedCNA
  • Cisco ASR 5000 Series Software VendorCisco Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:cisco:staros:*:*:*:*:*:*:*:*21.9.0 – 21.19.10VulnerableCisco
  • cpe:2.3:o:cisco:staros:*:*:*:*:*:*:*:* Versions 21.9.0 – 21.19.10 Vulnerable ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-1378
  2. 2026-10-03 Alias added: GHSA-qj86-q34h-pf43

References

Advisory 1

  • 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-2023-06755 Insufficiently protected credentials in Cisco ASR 5000 Series Software CVSS 3.1HIGH 8.8
See all 24 →

Sources

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