CVE-2021-40125: cisco adaptive_security_appliance_software Use After Free
Vulnerability summary
CVE-2021-40125 is a medium (CVSS 6.5) Use After Free vulnerability in cisco adaptive_security_appliance_software. EPSS estimates a 1.02% chance of exploitation in the next 30 days, higher than 62.8% of scored vulnerabilities.
Timeline
- 27-10-2021PublishedVulnerability first disclosed.
- 07-11-2024Last modifiedVulnerability information updated.
Description
A vulnerability in the Internet Key Exchange Version 2 (IKEv2) implementation of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to trigger a denial of service (DoS) condition on an affected device. This vulnerability is due to improper control of a resource. An attacker with the ability to spoof a trusted IKEv2 site-to-site VPN peer and in possession of valid IKEv2 credentials for that peer could exploit this vulnerability by sending malformed, authenticated IKEv2 messages to an affected device. A successful exploit could allow the attacker to trigger a reload of the device.
CVSS metrics
3 scores · 2 sources · 2 versions- CVE.orgCNA5.3MediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
EPSS trend
Probability
1.02%
Chance of exploitation in the next 30 days
Percentile
63%
Versus all other CVEs
30-day change
+0.01 pp
From 1.01% 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-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
- CWE-400Uncontrolled Resource ConsumptionThe product does not properly control the allocation and maintenance of a limited resource.
Affected systems
Cisco11 products
- adaptive_security_appliance_software≥ 9.8.0, < 9.8.4.40 | ≥ 9.9.0, < 9.12.4.30 | ≥ 9.14.0, < 9.14.3.9 | ≥ 9.15.0, < 9.15.1.17 | ≥ 9.16.0, < 9.16.2
- asa_5505_firmware009.016\(001.025\)
- asa_5512-x_firmware009.016\(001.025\)
- asa_5515-x_firmware009.016\(001.025\)
- asa_5525-x_firmware009.016\(001.025\)
1 vendor · 11 products
References
1 links- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ikev2-dos-g4cmrr7CVendor AdvisoryX Refsource CISCO