CVE-2021-1356: cisco cisco ios xe software Improper Input Validation

Vulnerability summary

CVE-2021-1356 is a medium (CVSS 4.3) Improper Input Validation vulnerability in cisco cisco ios xe software. EPSS estimates a 0.98% chance of exploitation in the next 30 days, higher than 61.7% of scored vulnerabilities.

Timeline

1. 24-03-2021
   PublishedVulnerability first disclosed.
2. 08-11-2024
   Last modifiedVulnerability information updated.

Description

Multiple vulnerabilities in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker with read-only privileges to cause the web UI software to become unresponsive and consume vty line instances, resulting in a denial of service (DoS) condition. These vulnerabilities are due to insufficient error handling in the web UI. An attacker could exploit these vulnerabilities by sending crafted HTTP packets to an affected device. A successful exploit could allow the attacker to cause the web UI software to become unresponsive and consume all available vty lines, preventing new session establishment and resulting in a DoS condition. Manual intervention would be required to regain web UI and vty session functionality. Note: These vulnerabilities do not affect the console connection.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
• CWE-755Improper Handling of Exceptional ConditionsThe product does not handle or incorrectly handles an exceptional condition.