CVE-2018-11518

Severity CVSS v4.0:

Pending analysis

Type:

CWE-20 Input Validation

Publication date:

30/05/2018

Last modified:

17/06/2026

Description

A vulnerability allows a phreaking attack on HCL legacy IVR systems that do not use VoIP. These IVR systems rely on various frequencies of audio signals; based on the frequency, certain commands and functions are processed. Since these frequencies are accepted within a phone call, an attacker can record these frequencies and use them for service activations. This is a request-forgery issue when the required series of DTMF signals for a service activation is predictable (e.g., the IVR system does not speak a nonce to the caller). In this case, the IVR system accepts an activation request from a less-secure channel (any loudspeaker in the caller&#39;s physical environment) without verifying that the request was intended (it matches a nonce sent over a more-secure channel to the caller&#39;s earpiece).

Impact

Vector 3.x

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 8.10 HIGH
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

8.10

Severity 3.x

HIGH

Vector 2.0

AV:N/AC:M/Au:N/C:P/I:P/A:P CVSS v2.0 Severity and Metrics:

Base Score: 6.80 MEDIUM
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P

Attack Vector (AV): Network
Attack Complexity (AC): Medium
Authentication (Au): None
Confidentiality (C): Physical
Integrity (I): Physical
Availability (A): Physical