What is CVE-2018-0273?

CVE-2018-0273 is a medium-severity vulnerability in Cisco Asr 5000, classified under CWE-399. CVSS score: 5.3/10. Published 2018-04-19.

How severe is CVE-2018-0273?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Cisco Asr 5000

CVE-2018-0273

A vulnerability in the IPsec Manager of Cisco StarOS for Cisco Aggregation Services Router (ASR) 5000 Series Routers and Virtualized Packet Core (VPC) System Software could allow an unauthenticated, remote attacker to terminate all active IPsec VPN tunnels and prevent new tunnels from being established, resulting in a denial of service (DoS) condition. The vulnerability is due to improper processing of corrupted Internet Key Exchange Version 2 (IKEv2) messages. An attacker could exploit this vulnerability by sending crafted IKEv2 messages toward an affected router. A successful exploit could allow the attacker to cause the ipsecmgr service to reload. A reload of this service could cause all IPsec VPN tunnels to be terminated and prevent new tunnels from being established until the service has restarted, resulting in a DoS condition. This vulnerability affects the following Cisco products when they are running Cisco StarOS: Cisco Aggregation Services Router (ASR) 5000 Series Routers, Virtualized Packet Core (VPC) System Software. Cisco Bug IDs: CSCve29605.

Published 2018-04-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.032 (87.8th percentile), scored 2026-10-20.

Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 87.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.031 · newest: 0.032 · change: +0.001

Affected products

Cisco Asr 5000
Cisco Asr 5500
Cisco Asr 5700
Cisco Staros — versions 19.4.2.65120, 19.6.0, 21.2.0
Cisco Staros Ipsec Manager — versions Cisco StarOS IPsec Manager

Weakness classification (CWE)

CWE-399

References

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418… (Vendor Advisory)
www.securityfocus.com/bid/103935 (VDB Entry, Third Party Advisory, vdb-entry)
www.securitytracker.com/id/1040721 (VDB Entry, Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2018-0273?: CVE-2018-0273 is a medium-severity vulnerability in Cisco Asr 5000, classified under CWE-399. CVSS score: 5.3/10. Published 2018-04-19.
How severe is CVE-2018-0273?: Medium severity. CVSS v3 base score is 5.3 out of 10.