CVE-2018-0277: A vulnerability in the Extensible Authentication Protocol-Transport Layer Security (EAP-TLS) certificate validation during EAP authentication for the ...

Description

A vulnerability in the Extensible Authentication Protocol-Transport Layer Security (EAP-TLS) certificate validation during EAP authentication for the Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause the ISE application server to restart unexpectedly, causing a denial of service (DoS) condition on an affected system. The vulnerability is due to incomplete input validation of the client EAP-TLS certificate. An attacker could exploit this vulnerability by initiating EAP authentication over TLS to the ISE with a crafted EAP-TLS certificate. A successful exploit could allow the attacker to restart the ISE application server, resulting in a DoS condition on the affected system. The ISE application could continue to restart while the client attempts to establish the EAP authentication connection. If an attacker attempted to import the same EAP-TLS certificate to the ISE trust store, it could trigger a DoS condition on the affected system. This exploit vector would require the attacker to have valid administrator credentials. The vulnerability affects Cisco ISE, Cisco ISE Express, and Cisco ISE Virtual Appliance. Cisco Bug IDs: CSCve31857.

Metrics

EPSS Probability

2.52%

82.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Identity Services Engine	2.0\(0.306\)
Cisco	Identity Services Engine	2.0\(1.130\)
Cisco	Identity Services Engine	2.1\(0.474\)
Cisco	Identity Services Engine	2.2\(0.470\)

References

http://www.securityfocus.com/bid/104212Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040922Third Party Advisory, VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180516-iseeapVendor Advisory
http://www.securityfocus.com/bid/104212Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040922Third Party Advisory, VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180516-iseeapVendor Advisory

Timeline

Published: May 17, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-0277?

A vulnerability in the Extensible Authentication Protocol-Transport Layer Security (EAP-TLS) certificate validation during EAP authentication for the Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause the ISE application server to restart unexpectedly, causing a denial of service (DoS) condition on an affected system. The vulnerability is due to incomplete input validation of the client EAP-TLS certificate. An attacker could exploit this vulnerability by initiating EAP authentication over TLS to the ISE with a crafted EAP-TLS certificate. A successful exploit could allow the attacker to restart the ISE application server, resulting in a DoS condition on the affected system. The ISE application could continue to restart while the client attempts to establish the EAP authentication connection. If an attacker attempted to import the same EAP-TLS certificate to the ISE trust store, it could trigger a DoS condition on the affected system. This exploit vector would require the attacker to have valid administrator credentials. The vulnerability affects Cisco ISE, Cisco ISE Express, and Cisco ISE Virtual Appliance. Cisco Bug IDs: CSCve31857.

How severe is CVE-2018-0277?

Severity scoring for CVE-2018-0277 is pending analysis. The EPSS model estimates a 2.52% probability of exploitation in the next 30 days.

How do I fix CVE-2018-0277?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.