CVE-2021-34705 vulnerability in Cisco Products
Published on September 23, 2021
Cisco IOS and IOS XE Software FXO Interface Destination Pattern Bypass Vulnerability
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.
Vulnerability Analysis
CVE-2021-34705 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, with no impact on integrity, and no impact on availability.
Weakness Type
Improper Handling of Undefined Values
The software does not handle or incorrectly handles when a value is not defined or supported for the associated parameter, field, or argument name.
Products Associated with CVE-2021-34705
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Affected Versions
Cisco IOS Version n/a is affected by CVE-2021-34705Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.