CVE-2021-34705 Cisco IOS and IOS XE Software FXO Interface Destination Pattern Bypass Vulnerability

2021-09-2200:00:00

CWE-232

cisco

www.cve.org

5.3 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

LOW

Availability Impact

NONE

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

0.001 Low

EPSS

Percentile

47.9%

JSON

A vulnerability in the Voice Telephony Service Provider (VTSP) service of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass configured destination patterns and dial arbitrary numbers. This vulnerability is due to insufficient validation of dial strings at Foreign Exchange Office (FXO) interfaces. An attacker could exploit this vulnerability by sending a malformed dial string to an affected device via either the ISDN protocol or SIP. A successful exploit could allow the attacker to conduct toll fraud, resulting in unexpected financial impact to affected customers.

CNA Affected

[
  {
    "product": "Cisco IOS ",
    "vendor": "Cisco",
    "versions": [
      {
        "status": "affected",
        "version": "n/a"
      }
    ]
  }
]