CVE-2021-1356 Explained : Impact and Mitigation

Cisco IOS XE Software is affected by multiple vulnerabilities in the web UI, allowing an authenticated attacker to cause a denial of service (DoS) condition. Here's what you need to know about CVE-2021-1356.

Understanding CVE-2021-1356

This CVE identifies multiple vulnerabilities in the web UI of Cisco IOS XE Software that could be exploited by an authenticated, remote attacker.

What is CVE-2021-1356?

CVE-2021-1356 refers to the vulnerabilities in the web UI of Cisco IOS XE Software that could lead to a DoS condition when exploited by an attacker with read-only privileges.

The Impact of CVE-2021-1356

The vulnerabilities allow an attacker to render the web UI unresponsive, consuming vty line instances and causing a DoS condition. Manual intervention is needed to restore functionality.

Technical Details of CVE-2021-1356

The following technical details provide insight into the vulnerability.

Vulnerability Description

Insufficient error handling in the web UI allows attackers to send crafted HTTP packets, leading to unresponsive web UI software and a DoS condition.

Affected Systems and Versions

The affected product is Cisco IOS XE Software, with versions susceptible to these vulnerabilities.

Exploitation Mechanism

Authenticated attackers with read-only privileges can exploit the vulnerabilities by sending crafted HTTP packets to the targeted device.

Mitigation and Prevention

Understanding how to mitigate and prevent the impact of CVE-2021-1356 is crucial for maintaining cybersecurity.

Immediate Steps to Take

Immediately applying provided patches and updates is essential to mitigate the risk of exploitation.

Long-Term Security Practices

Regular security updates, network monitoring, and access control mechanisms are essential for long-term security.

Patching and Updates

Staying informed about security advisories and promptly applying patches released by Cisco is crucial to prevent exploitation.