CVE-2021-1493: Cisco Adaptive Security Appliance Software

High severity, CVSS 7.1. EPSS: 1.2% chance of exploitation in the next 30 days.

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to cause a buffer overflow on an affected system. The vulnerability is due to insufficient boundary checks for specific data that is provided to the web services interface of an affected system. An attacker could exploit this vulnerability by sending a malicious HTTP request. A successful exploit could allow the attacker to cause a buffer overflow condition on the affected system, which could disclose data fragments or cause the device to reload, resulting in a denial of service (DoS) condition.

Affected products

• Cisco Adaptive Security Appliance Software: from 9.8, before 9.8.4.34 (fixed in 9.8.4.34); from 9.9, before 9.9.2.85 (fixed in 9.9.2.85); from 9.10, before 9.12.4.13 (fixed in 9.12.4.13); from 9.13, before 9.13.1.21 (fixed in 9.13.1.21); from 9.14, before 9.14.2.8 (fixed in 9.14.2.8); from 9.15, before 9.15.1.7 (fixed in 9.15.1.7)
• Cisco Secure Firewall Threat Defense: before 6.4.0.12 (fixed in 6.4.0.12); from 6.5.0, before 6.6.3 (fixed in 6.6.3); from 6.7.0, before 6.7.0.1 (fixed in 6.7.0.1)

Published 2021-04-29. Last modified 2026-08-11.