CVE-2021-1493: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services Buffer Overflow Denial of Service Vulnerability

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-04-29 · updated 2026-08-11
Weakness: CWE-120

Description

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 ASA Software: from 9.8 before 9.8.4.34; from 9.9 before 9.9.2.85; from 9.10 before 9.12.4.13; from 9.13 before 9.13.1.21; from 9.14 before 9.14.2.8; from 9.15 before 9.15.1.7 — fixed in 9.12.4.13, 9.13.1.21, 9.14.2.8, 9.15.1.7, 9.8.4.34, 9.9.2.85
Cisco Firepower Threat Defense Software: before 6.4.0.12; from 6.5.0 before 6.6.3; from 6.7.0 before 6.7.0.1 — fixed in 6.4.0.12, 6.6.3, 6.7.0.1

How to fix

Upgrade to a fixed version: Cisco ASA Software 9.12.4.13, 9.13.1.21, 9.14.2.8, 9.15.1.7; Cisco Firepower Threat Defense Software 6.4.0.12, 6.6.3, 6.7.0.1. Check the vendor advisory for mitigations.

References

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