Cisco ASA Uncontrolled Resource Consumption (CVE-2018-15399)

medium Tenable OT Security Plugin ID 506049

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability in the TCP syslog module of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to exhaust the 1550-byte buffers on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to a missing boundary check in an internal function. An attacker could exploit this vulnerability by establishing a man-in-the-middle position between an affected device and its configured TCP syslog server and then maliciously modifying the TCP header in segments that are sent from the syslog server to the affected device. A successful exploit could allow the attacker to exhaust buffer on the affected device and cause all TCP-based features to stop functioning, resulting in a DoS condition. The affected TCP-based features include AnyConnect SSL VPN, clientless SSL VPN, and management connections such as Secure Shell (SSH), Telnet, and HTTPS.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

Refer to the vendor advisory.

Plugin Details

Severity: Medium

ID: 506049

File Name: tenable_ot_cisco_CVE-2018-15399.nasl

Version: 1.2

Type: Remote

Family: Tenable.ot

Published: 10/5/2026

Updated: 10/6/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3.3

Percentile: 50.7

CVSS v2

Risk Factor: High

Base Score: 7.1

Temporal Score: 5.3

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

CVSS Score Source: CVE-2018-15399

CVSS v3

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.9

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:cisco:adaptive_security_appliance_software:9.4%284%29, cpe:/o:cisco:adaptive_security_appliance_software:9.8%282%29

Required KB Items: Tenable.ot/Cisco

Exploit Ease: No known exploits are available

Patch Publication Date: 10/5/2018

Vulnerability Publication Date: 10/5/2018

Reference Information

CVE: CVE-2018-15399

CWE: 400, 770

Detections

Analytics