CVE-2021-1493 Memory corruption in Cisco Adaptive Security Appliance (ASA) Software
An authenticated remote attacker can trigger a buffer overflow in Cisco ASA/FTD web services, causing device reload or data disclosure.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-1493?
CVE-2021-1493 is a high-severity memory corruption vulnerability in Cisco Adaptive Security Appliance Software, published on 29 Apr 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-120
Which versions are affected by CVE-2021-1493?
It affects 2 products.
Products include Cisco Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense.
How do I fix CVE-2021-1493?
No fix has been published for CVE-2021-1493 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2021-1493 being exploited?
There is no known exploitation of CVE-2021-1493 in the wild and no public exploit code.
Other vulnerabilities in Cisco Adaptive Security Appliance Software
- CVE-2025-20333 Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow
- CVE-2016-6366 Cisco Adaptive Security Appliance (ASA) SNMP Buffer Overflow
- CVE-2026-20349 Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection
- CVE-2024-20353 Cisco ASA and FTD Denial of Service
- CVE-2016-6367 Cisco Adaptive Security Appliance (ASA) CLI Remote Code Execution
All Cisco Adaptive Security Appliance Software vulnerabilities
Sources
Also known as GHSA-4f73-r2j2-j4h5.