CVE-2021-40118: cisco adaptive_security_appliance Stack-based Buffer Overflow
Vulnerability summary
CVE-2021-40118 is a high (CVSS 8.6) Stack-based Buffer Overflow vulnerability in cisco adaptive_security_appliance. EPSS estimates a 1.36% chance of exploitation in the next 30 days, higher than 71.3% of scored vulnerabilities.
Timeline
- 27-10-2021PublishedVulnerability first disclosed.
- 07-11-2024Last modifiedVulnerability information updated.
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 unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to improper input validation when parsing HTTPS requests. An attacker could exploit this vulnerability by sending a malicious HTTPS request to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HDiffers
EPSS trend
Probability
1.36%
Chance of exploitation in the next 30 days
Percentile
71%
Versus all other CVEs
30-day change
+0.01 pp
From 1.35% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-121Stack-based Buffer OverflowA stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
- CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.
Affected systems
Cisco12 products
- adaptive_security_appliance< 9.8.4.40
- adaptive_security_appliance_software≥ 9.9.0, < 9.12.4.29 | ≥ 9.13.0, < 9.14.3.9 | ≥ 9.15.0, < 9.15.1.17 | ≥ 9.16.0, < 9.16.2.3
- asa_5505_firmware009.012\(004.024\) | 009.015\(001\) | 009.015\(001.015\) | 009.015\(001.016\) | 009.016\(001\)
- asa_5512-x_firmware009.012\(004.024\) | 009.015\(001\) | 009.015\(001.015\) | 009.015\(001.016\) | 009.016\(001\)
- asa_5515-x_firmware009.012\(004.024\) | 009.015\(001\) | 009.015\(001.015\) | 009.015\(001.016\) | 009.016\(001\)
1 vendor · 12 products
References
1 links- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asafdt-webvpn-dos-KSqJAKPAVendor AdvisoryX Refsource CISCO