CVE-2021-1493
Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services Buffer Overflow Denial of Service Vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.5
Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services Buffer Overflow Denial of Service Vulnerability
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.
- Record
CVE-2021-1493- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
EUVDEUVD-2021-6960
8.5
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.
- Record
EUVD-2021-6960- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-4f73-r2j2-j4h5
7.1
A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software...
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.
- Record
GHSA-4f73-r2j2-j4h5- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
NVD
8.5
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.
- Record
CVE-2021-1493- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:H - CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:S/C:P/I:N/A:C - Weakness
- CWE-120
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-1493 is a high vulnerability (CVSS 8.5) in Cisco Adaptive Security Appliance Software, published April 29, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.21%, the 68th percentile. No source names a fixed version.