CVE-2021-34705 : What You Need to Know

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.

Understanding CVE-2021-34705

This CVE identifies a vulnerability in Cisco IOS and IOS XE Software that could be exploited by attackers to conduct toll fraud.

What is CVE-2021-34705?

The vulnerability allows unauthenticated attackers to dial arbitrary numbers by exploiting insufficient validation of dial strings at FXO interfaces.

The Impact of CVE-2021-34705

Successful exploitation could lead to toll fraud and result in unexpected financial losses for affected customers.

Technical Details of CVE-2021-34705

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability in Cisco IOS and IOS XE Software allows attackers to bypass configured destination patterns and dial arbitrary numbers.

Affected Systems and Versions

The vulnerability affects Cisco IOS with no specific version mentioned in the advisory.

Exploitation Mechanism

Attackers can exploit the vulnerability by sending a malformed dial string via the ISDN protocol or SIP.

Mitigation and Prevention

Learn about the steps to mitigate and prevent exploitation of CVE-2021-34705.

Immediate Steps to Take

Organizations using affected Cisco IOS and IOS XE Software should apply patches or workarounds provided by Cisco.

Long-Term Security Practices

Implement strict access controls, network segmentation, and regular security updates to prevent future vulnerabilities.

Patching and Updates

Stay informed about security advisories from Cisco and apply patches promptly to secure systems.