Cisco Email Security Appliance Multiple DoS Vulnerabilities (cisco-sa-20190109-esa-dos / cisco-sa-20190109-esa-url-dos)

High Nessus Plugin ID 121248


The remote device is missing a vendor-supplied security patch.


According to its self-reported version, the Cisco Email Security Appliance (ESA) is affected by the following vulnerabilities:

- A denial of service (DoS) vulnerability exists in Secure/Multipurpose Internet Mail Extensions (S/MIME) Decryption and Verification and S/MIME Public Key Harvesting features due to improper input validation of S/MIME-signed emails. An unauthenticated, remote attacker can exploit this issue, via malicious S/MIME-signed email, to cause the process to stop responding. (CVE-2018-15453)

- A denial of service (DoS) vulnerability exists in email message filtering feature due to improper filtering of email messages that contain references to whitelisted URLs. An unauthenticated, remote attacker can exploit this issue, via malicious email message that contains a large number of whitelisted URLs, to cause the system to stop responding (CVE-2018-15460).


Upgrade to the relevant fixed version referenced in Cisco Security Advisory cisco-sa-20190109-esa-dos and cisco-sa-20190109-esa-url-dos.

See Also

Plugin Details

Severity: High

ID: 121248

File Name: cisco-sa-20190109-esa-dos.nasl

Version: 1.2

Type: combined

Family: CISCO

Published: 2019/01/18

Updated: 2019/07/18

Dependencies: 69075

Risk Information

Risk Factor: High

CVSS Score Source: CVE-2018-15453

CVSS Score Rationale: Based on vendor advisory.

CVSS v2.0

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS v3.0

Base Score: 8.6

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Vulnerability Information

CPE: cpe:/o:cisco:email_security_appliance_firmware

Required KB Items: Host/AsyncOS/Cisco Email Security Appliance/Version

Patch Publication Date: 2019/01/09

Vulnerability Publication Date: 2019/01/09

Reference Information

CVE: CVE-2018-15453, CVE-2018-15460

BID: 106507, 106511