CVE-2021-34787 json
Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Identity-Based Rule Bypass Vulnerability
published 2021-10-27 5 y ago modified 2026-08-11 2 mo ago also EUVD-2021-21437
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.0%
- EPSS 1.0% chance of exploitation in 30 days, percentile 64%
- public exploits
- 0
- none known
Summary
A vulnerability in the identity-based firewall (IDFW) rule processing feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass security protections. This vulnerability is due to improper handling of network requests by affected devices configured to use object group search. An attacker could exploit this vulnerability by sending a specially crafted network request to an affected device. A successful exploit could allow the attacker to bypass access control list (ACL) rules on the device, bypass security protections, and send network traffic to unauthorized hosts.
Patch / fix
- cisco adaptive_security_appliance 9.8.4.40
- cisco secure_firewall_threat_defense 6.4.0.13, 6.6.5, 6.7.0.3, 7.0.1
- cisco adaptive_security_appliance_software 9.12.4.25, 9.14.3.1, 9.15.1.17, 9.16.1.28
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2 y ago
Exploit prediction
1.04% chance of exploitation in the next 30 days, higher than 64% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:N/I:P/A:N |
Affected products
- Cisco Cisco Adaptive Security Appliance (ASA) Software
Classification
References
Sources
- CVE List CVE-2021-34787
- NVD CVE-2021-34787
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